ES2931216A1 - COOLING/HEATING PROCESS AND DEVICE BASED ON MOLECULAR ORGANIC-INORGANIC HYBRID COMPOUNDS (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

Cooling/heating methods based on molecular organic-inorganic hybrid compounds. Cooling/heating process induced by an external stimulus that comprises the application and removal of a stimulus that is selected from the group consisting of hydrostatic pressure, uniaxial pressure, and uniaxial tension, on a molecular organic-inorganic hybrid material of general formula AB (I), A 2 B (II) and AB 2(III), where: A and B are organic ions, organometallic ions, coordination complex ions, monatomic inorganic ions and/or polyatomic inorganic ions. Device with cooling/heating capacity induced by an external stimulus, comprising the hybrid materials defined above, in addition to the hybrid materials listed in the present invention. (Machine-translation by Google Translate, not legally binding)

Description

DESCRIPTION

Cooling/heating process and device based on molecular organic-inorganic hybrid compounds

The present invention is related to cooling/heating methods based on the use of crystalline molecular organic-inorganic hybrid compounds, which present a phase transition that is very sensitive to external mechanical stimuli, together with a device comprising the aforementioned mechanocaloric materials. and means to apply mechanical stimuli, as well as the use of the caloric effect of new mechanocaloric molecular organic-inorganic hybrid compounds for refrigeration and heating applications.

STATE OF THE ART

According to recent reports from the International Energy Agency, around 20% of global energy consumption is dedicated to refrigerating food, beverages, medicines, electronic devices, machines, vehicles and/or homes. Furthermore, this consumption is expected to triple by 2050, with predictions estimating that, by then and for the first time in history, more energy will be used for cooling than for heating. Current refrigeration technologies are based on the compression/expansion of gases at relatively low pressures, which can range from tens to just over a hundred bars. However, most of these machines work with greenhouse gases (1,1,1,2-tetrafluoroethane - R134a -, 1,1,1-trichloroethane - R140a - or carbon dioxide - R744 -), toxic chemical compounds (ammonia - R717 -), or flammable compounds (propane - R290-, isobutane - R600a -or propylene - R1270 -). In this way, any refrigerant gas leak due to a break in the refrigeration machine or during the manufacture, handling or transport of these gases, poses a considerable risk to the environment, the operator and/or the end user.

Given this scenario, a hundred countries, including the European Union and the United States, are restricting the use of greenhouse gases for refrigeration (see the Figali Amendment to the Montreal Protocol and EU Regulation No. 517/ 2014, as an example) and are promoting the search for new ecological and safe alternatives for the user.

In recent years, solids called mechanocaloric materials have proven to be a promising alternative to refrigeration gases. Mechanocaloric materials are solid substances that undergo large thermal changes (isothermal entropy changes and/or adiabatic temperature changes) through the application of external mechanical stimuli. Stimuli that induce these mechanocaloric effects include hydrostatic pressure, as well as uniaxial pressure and tension. Therefore, the mechanocaloric materials known up to now are divided into (i) barocaloric materials (when the mechanocaloric effect is induced by hydrostatic pressure) and (ii) elastocaloric materials (when the caloric effect is induced by uniaxial pressure or stress). Nowadays, known mechanocaloric materials are scarce, and they are generally expensive materials (such as metals or rare earth alloys), and/or require relatively high pressures to be able to present the desired caloric effect for cooling (p > 1000 bar) ( see X. Moya et al., Nature Materials, 2014, vol 13, pp 439-450).

In this sense, organic-inorganic hybrid compounds have undergone rapid development in recent years. These hybrid organic-inorganic compounds contain components of both organic and inorganic nature in their crystalline structure. These compounds can be classified as polymeric organic-inorganic hybrid compounds or molecular organic-inorganic hybrid compounds, depending on the strength of chemical interaction between their organic and inorganic components. Polymeric organic-inorganic hybrid compounds are non-molecular hybrid compounds that form extensive 1D, 2D, and/or 3D structures resulting from strong chemical interactions between their constituents. Meanwhile, molecular organic-inorganic hybrid compounds are ionic salts based on weaker chemical interactions between charged organic or inorganic ions, which are isolated and do not form dimensional lattices like the previous ones, resulting in materials that are more flexible and sensitive to pressure. Pressure. In addition, molecular organic-inorganic hybrid materials, by not forming dimensional lattices, allow their atoms to have a higher degree of freedom (they are less fixed in their positions), which can generate larger thermal changes (for example, entropy changes) when different external stimuli are applied to them (for example, pressure and/or temperature).

So far some, although very few, hybrid materials have been reported. polymeric organic-inorganic compounds (non-molecular hybrid compounds) with barocaloric effect for refrigeration applications. Among them are non-molecular hybrid compounds with the general formula [(CH3CH2CH2)4N]M[N(CN)2]3, where M = Mn2+, or Cd2+, (see JM Bermúdez-García et al. Nature Communications, 2017, 8 , 15715; JM Bermúdez-García et al. Journal of Materials Chemistry C, 2018, 6 (37), 9867-9874), the compound [(CH3)2NH2]Mg[HCOO]3 (see M. Szafranski et al. APL Materials 2018, 6 , 100701, CN107418517B), the compound [(CH3)4N]Mn[N3]3 (see J. Salgado-Beceiro et al. Materials Advances, 2020, 1, 3167-3170), and compounds with hexagonal packing and general formula ABX3, where A is an organic cation or a mixture of organic cations, B are metal cations and X are halides (see WO2019081799A1). In addition, it has also been theoretically predicted that another 16 polymeric organic-inorganic hybrid compounds could show barocaloric effect, although this effect has not been demonstrated experimentally. (see JM Bermúdez-García et al. in J. Phys. Chem. Lett., 2017, 8, 4419-4423).

In this context, it is important to note that polymeric organic-inorganic hybrid compounds (non-molecular hybrid compounds) have experimentally exhibited a giant barocaloric effect (AS = 10 - 40 J K-1 kg-1). However, the strong chemical bonds present in non-molecular polymeric organic-inorganic hybrid compounds limit their degree of freedom, and therefore their giant barocaloric effects are limited and cannot be further improved.

In view of the state of the art, there is still a great margin for improvement to offer new solid-state caloric materials that can be useful for refrigeration/heating applications. In this sense, it is desirable to find new materials that present higher barocaloric effects (AS > 40 J K-1 kg-1). These specifications would open the door to a greater number of cooling/heating applications, reducing the economic cost and environmental impact of these technologies.

EXPLANATION OF THE INVENTION

The inventors' experimental work has shown that molecular organic-inorganic hybrid compounds of the general formula AB(I), A2B(II) or AB2(III) can exhibit enhanced barocaloric effects. In these materials, A and B are cations and anions, respectively. Here, A comprises organic cations, cations organometallics, coordination complex cations, monatomic inorganic cations, polyatomic inorganic cations, or a mixture of any of the foregoing; and B comprises coordination complex anions, monatomic inorganic anions, polyatomic inorganic anions, organic anions, organometallic anions, or a mixture of any of the foregoing; always keeping in mind that both inorganic ions and organic ions must be present in the formula to meet the definition of molecular organic-inorganic hybrid compound. Furthermore, compared to polymeric hybrids, these molecular organic-inorganic hybrid compounds exhibit much weaker interactions between organic and inorganic components. This favors solid-solid phase transitions induced by external stimuli (such as hydrostatic pressure) with enhanced barocaloric effects (AS > 40 J K-1 kg-1), relatively larger latent heat ( dH = [7.8 - 48.4] kJ kg -1) and whose transition temperatures can be actively modified by applying pressure (with a pressure dependency of dTt/dp = [7.1 - 35.0] K kbar-1). Therefore, these materials can be used more efficiently in both cooling and heating applications.

The refrigeration capacity of these materials is associated with isothermal changes in entropy (AS) or adiabatic changes in temperature ( AT) induced by the application of external mechanical forces when the material is at a temperature close to its solid-transition temperature. solid (Tt), which marks the working temperature of such materials, that is, the temperature at which the material can provide cooling in a given device.

One of the advantages of using molecular organic-inorganic hybrid compounds, such as those described in the present invention, in a refrigeration process is that they are solid materials and, therefore, they avoid the use of gases and dangerous pollutants and allow refrigeration systems. more compact. In addition, they are easy to handle and, in the event of an accidental leak, are easier to contain and recover than a gas or liquid. The molecular organic-inorganic hybrid compounds of the present invention are much cheaper materials than rare earth metals and alloys used as heat materials, and are more sensitive to hydrostatic pressure and uniaxial mechanical stimuli. Additionally, these materials are lightweight, which lightens the weight of the cooling device. Furthermore, they have gigantic (AS > 40 J K-1 kg-1) and even colossal (AS > 100 J K-1 kg-1) barocaloric effects in a wider range of operating temperatures and close to room temperature (Top = [- 10-132°C]), and at lower pressures (Ap < 1000 bar) than most barocaloric materials.

It must be taken into account that any mechanocaloric refrigeration process (including barocaloric) generates in turn a quantity of heat that, if it does not want to be used, must be directed to a heat sink to be dispersed in the environment. Similarly, the generated heat can also be used in heating applications. Therefore, methods that allow the use of molecular organic-inorganic hybrid compounds as cooling agents can also be adapted for the use of these same compounds as heating agents.

These molecular organic-inorganic hybrid materials are also much more flexible than caloric materials based on metals and rare earth alloys, and can be used in flexible devices, such as shoe insoles, textile garments, phones, and flexible electronic devices, etc.

Contrary to the case of hybrid organic-inorganic polymeric materials with the general formula [(CH3CH2CH2)4N]M[N(CN)2]3 and ABX3 (which have a crystalline lattice structure formed by strong interactions between the different components organic and inorganic, fully integrated into the resulting network); In the molecular organic-inorganic hybrid compounds of the general formula AB (I), A2B (II) or AB2 (III) of the present invention, the ionic species A and B retain their entity and characteristics and are linked only by weak electrostatic interactions in crystal, which allows a greater degree of freedom of its organic and inorganic ionic components and, therefore, a greater barocaloric effect compared to polymeric hybrids.

The barocaloric effect of the compounds AB (I), A2B (II) and AB2 (III) of the current invention is considerably larger than the effect observed in the compounds [(CH3CH2CH2)4N]M[N(CN)2]3 and ABX3, In addition, these compounds can operate in a wider temperature range and close to room temperature, which greatly facilitates their application as refrigeration materials.

In the present invention, not only hydrostatic pressure can be used as the external stimulus, but also other mechanical stimuli such as uniaxial pressure and tension. They can be used to induce solid-solid phase transition for barocaloric and elastocaloric heating/cooling applications.

The barocaloric effect and the elastocaloric effect are both induced by a mechanical stimulus, the first by hydrostatic pressure (pressure exerted equally on the entire surface of a given material), and the second by compression and/or uniaxial tension (force exerted only along the surface of a given material). along an axis of a certain material). Thus, large thermal changes (isothermal changes in entropy, AS, or adiabatic changes in temperature, AT) are induced by applying hydrostatic pressure or a uniaxial mechanical force. The elastocaloric effect is advantageous in those cases in which the material deforms more in one axis than in another, but -in general- both effects can be considered relatively similar.

Finally, the compounds of the present invention have the additional advantage (over other known polymeric organic-inorganic hybrid compounds) of being deformable plastic materials, which makes them less susceptible to mechanical fracture during use in cooling/heating devices. .

Thus, a first aspect of the present invention is related to a cooling/heating process that comprises the application of an external stimulus that is selected from the group consisting of hydrostatic pressure, uniaxial pressure, and uniaxial tension, to an organic-inorganic hybrid compound. general formula molecule:

AB(I), A2B(II) or AB2(III)

where:

the molecular organic-inorganic hybrid compound comprises inorganic ions and organic ions;

A is selected from the group consisting of an organic cation, an organometallic cation, a mixture of organic and organometallic cations, a coordination complex cation, a monatomic inorganic cation, a polyatomic inorganic cation, and a mixture of any of the above in any atomic ratio;

and B is selected from the group consisting of a coordination complex anion, a monatomic inorganic anion, a polyatomic inorganic anion, an organic anion, an organometallic anion, and a mixture of any of the foregoing in any atomic ratio;

when A is an organic cation, it is selected from the group consisting of trimethylsulfonium ([(CH3)3S]+), 1-chloro-methyl-trimethylammonium ([(CH3)3(CH2Cl)N]+), 1-chloro- methyl-triethylammonium ([(CH3CH2)3(CH2Cl)N]+), 1-chloro-methyl-tripropylammonium ([(CH3CH2CH2)3(CH2Cl)N]+), tetramethylammonium ([(CH)4N]+), dibutylammonium ([(CH3CH2CH2CH2)2NH2]+), R1R2R3R4N+, R1R2R3R4P+, R1R2R3S+' and R1R2R3S;

when A is an organometallic cation, it is selected from the group consisting of cations of the general formula [MLq]p+, where M is bound to either ligands L of the same or different types;

when A is a mixture of organic and organometallic cations, said mixture comprises any of the aforementioned organic and organometallic cations in any atomic ratio;

when A is a coordination complex cation, it is selected from the group consisting of cations of the general formula [ML1q]p+, where M is bound to either L1 ligands of the same or different types;

when A is a monatomic inorganic cation, it is selected from the group consisting of Na+, K+, Cs+, Rb+, Mg2+, Ca2+, Sr2+, and Ba2+;

when A is a polyatomic inorganic cation, it is selected from the group consisting of [NH4]+, [NF4]+, [N2H5E, and a mixture thereof;

when A is a mixture of cations, said mixture comprises any of the aforementioned organic cations, organometallic cations, coordination complex cations, monatomic inorganic cations and/or polyatomic inorganic cations, in any atomic ratio;

When B is a coordination complex anion, is selected from the group consisting of anions of the general formula [ML1q]p-, M is bound to either L1 ligands of the same or different types;

when B is a monatomic inorganic anion, it is selected from the group consisting of F-, Cl-, Br-, and I-;

when B is a polyatomic inorganic anion, it is selected from the group consisting of is selected from the group consisting of [PF6]-, [BF4]-, [N(CN)2]-, [H2PO2]-, [H2PO4] -, [HPO4]2-, [PO4]3-, [SO4]2-, [SCN]-, [CN]-, [N3]-, and a mixture thereof;

when B is an organic anion, it is selected from the group consisting of [HCOO]-, R1R2R3R4O-, -OR1R2R3R4O-, and R1R2R3S-;

when B is an organometallic anion, it is selected from the group consisting of anions of the general formula [MLq]p-, where M is bound to either ligands L of the same or different types;

when B is a mixture of anions, said mixture comprises any of the aforementioned coordination complex anions, monatomic inorganic anions, polyatomic inorganic anions, organic anions and/or organometallic anions, mentioned above in any atomic ratio;

where:

R1, R2, R3, and R4 are independently selected from the group consisting of non-metallic elements, and (C5-C10)-heterocyclic cations;

non-metallic elements are elements of the periodic table that are not metals;

M is independently selected from the group consisting of transition metals, lanthanides, Al, Ga, Ge, In, Sn, Pb, Bi, and a mixture of these,

L is an organic ligand that is chemically bonded to M via at least one carbon-metal (CM) bond and is independently selected from the group consisting of (C1-C10)-alkyl, (C1-C10)-alkylidene, ( C1-C10)- (C1-C10)-alkylidyne, (C1-C10)alkene, (Ci-Cio)-allyl, 1,3-butadiene, cyclobutadiene, cyclopentadienyl, cyclooctatetraene, 2,4,6-tris(trifluoromethyl)phenyl (Fmes), a mixture of any of these, and a mixture of these with halide anions,

L1 is independently selected from the group consisting of halide, sulfide (S2-), amino (NH3), aqua (H2O), bipyridyl (bpy), ethylenediamine (en), acetylacetonate (acac), oxalate (ox), acetate ( oac), cyanide (CN-), thiocyanate (NCS-), isothiocyanate (SCN-), and a mixture thereof;

the halide ligands are F-, Cl-, Br- and I-; and p and q are independently an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, and 9.

The cooling process can be exploited in a continuous heating/cooling cycle.

In a particular embodiment, A is an organic cation selected from the group consisting of trimethylsulfonium ([(CH3)3S]+), 1-chloro-methyl-trimethylammonium ([(CH3)3(CH2Cl)N]+), 1-chloro-methyl-triethylammonium ([(CH3CH2)3(CH2Cl)N]+), 1-chloro-methyl-tripropylammonium ([(CH3CH2CH2)3(CH2Cl)N]+), tetramethylammonium ([(CH3)4N] +), dibutylammonium ([(CH3CH2CH2CH2)2NH2]+), R1R2R3R4N+, R1R2R3R4P+, R1R2R3S+ or R1R2R3S (where R1, R2, R3, and R4 are one or more non-metallic elements) and/or cations (C5-C10)- heterocyclics (derived from cubano, twistane, prismane, norbornane, basketane, oxazoline, tropane, imidazole, adamantane, thiophene, pyridine, piperidine, piperazine, etc.). In an even more particular embodiment, R1, R2, R3, and R4 are non-metallic elements selected from the group consisting of hydrogen, carbon, nitrogen, oxygen, F-, Cl-, Br-, and I-.

In another particular embodiment, A is an organometallic cation that is selected from the group consisting of [MLq]p+ cations, where M is selected from the group of transition metals, lanthanides, Al, Ga, Ge, In, Sn, Pb, Bi , and a mixture of these, L is an organic ligand that is chemically bonded to M via at least one carbon-metal bond (CM) and is selected from the group consisting of ligands (C1-C10)-alkyl, (C1-C10 )-alkylidene, (C1-C10)-(C1-C10)-alkylidyno, (C1-C10)-alkene, (C1-C10)-allyl, 1,3-butadiene, cyclobutadiene, cyclopentadienyl, cyclooctatetraene, 2,4, 6-tris(trifluoromethyl)phenyl (Fmes), a mixture of any of these, or a mixture of these with halide anions, and p and q are any number from 1, 2, 3, 4, 5, 6, 7, 8, or 9. In this case, M can be bound to ligands L of the same type (homoleptic cation) or of different types (cation heteroleptic). In an even more particular embodiment, A is selected from the group consisting of cobalt(III) bis(cyclopentadienyl) ([Cp2Co]+) and iron(III) bis(cyclopentadienyl) ([Cp2Fe]+).

In another particular embodiment, A is a mixture of any of the organic cations and organometallic cations mentioned above.

In another particular embodiment, A is a coordination complex cation that is selected from the group consisting of [ML1q]p+ cations, where M is selected from the group consisting of transition metal, lanthanide, Al, Ga, Ge cations , In, Sn, Pb, Bi, or a mixture thereof, L1 is selected from the group consisting of halide (F-, Cl-, Br-, I-), sulfide (S2-), amino (NH3), aqueous (H2O), bipyridyl (bpy), ethylenediamine (en), acetylacetonate (acac), oxalate (ox), acetate (oac), cyanide (CN-), thiocyanate (NCS-) or isothiocyanate (SCN-) or a mixture of these, and p and q are any number of 1,2, 3, 4, 5, 6, 7, 8, or 9. In this case, M can be bound to L1 ligands of the same type (homoleptic cation) or of different types (cation heteroleptic). In an even more particular embodiment, A is selected from the group consisting of [Co(NH3)6]3+, [Co(NH3)5Cl]2+, [Co(NH3)4Cl2]+, and [Co(en) 2Cl2]+.

In another particular embodiment, A is a monatomic inorganic cation that is selected from the group consisting of Na+, K+, Cs+, Rb+, Mg2+, Ca2+, Sr2+, and Ba2+.

In another particular embodiment, A is a polyatomic inorganic cation selected from the group consisting of [NH4E [NF4E [N2H5E] and a mixture thereof.

In another particular embodiment, A is a mixture of any of the previously mentioned organic cations, organometallic cations, coordination complex cations, monatomic inorganic cations and/or polyatomic inorganic cations.

In a particular embodiment, B is a coordination complex anion that is selected from the group consisting of [ML1q]p- anions, where M is selected from the group consisting of transition metal cations, lanthanides, Al, Ga, Ge , In, Sn, Pb, Bi, or a mixture thereof, L1 is selected from the group consisting of halide (F-, Cl-, Br-, I-), sulfide (S2-), amino (NH3), aqua (H2O), bipyridyl (bpy), ethylenediamine (en), acetylacetonate (acac), oxalate (ox), acetate (oac), cyanide (CN-), thiocyanate (NCS-), isothiocyanate (SCN-), and a mixture of these, and p and q are any number from 1, 2, 3, 4, 5, 6, 7, 8 or 9. In this case, M can be bound to L1 ligands of the same type (homoleptic cation) or of different types (heteroleptic cation). In an even more particular embodiment, B is selected from the group consisting of [FeCU]-, [CoCU]-, [GaCU]-, [MnCU]2, [FeBr4]-, [CoBr4]-, [GaBr4]-, [MnBr4]2-, [Au(CN)2]-, [Ag(CN)2]-, [CoCl6]3-, [Co(NH3)Cl5]2- and [Co(NH3)2Cl4]-.

In another particular embodiment, B is a monatomic inorganic anion selected from the group consisting of F-, Cl-, Br-, and I-.

In another particular embodiment, B is a polyatomic inorganic anion selected from the group consisting of [PF6]-, [BF4]-, [N(CN)2]-, [H2PO2]-, [H2PO4]-, [HPO4 ]2-, [PO4]3-, [SO4]2-, [SCN]-, [CN]-, [N3]-, and a mixture of these.

In another particular embodiment, B is a mixture of any of the aforementioned coordination complex anions, monatomic inorganic anions and/or polyatomic inorganic anions.

In another particular embodiment, B is an organic anion that is selected from the group consisting of [HCOO]-, R1R2R3R4O-, -OR1R2R3R4O-, or R1R2R3S- (where R1, R2, R3 and R4 are one or more non-metallic elements ) or (C5-C10)-heterocyclic anions.

In another particular embodiment, B is an organometallic anion that is selected from the group consisting of cations [MLq]p-, where M is selected from the group of transition metals, lanthanides, Al, Ga, Ge, In, Sn, Pb, Bi, or a mixture thereof, L is an organic ligand that is chemically bonded to M via at least one carbon-metal bond (CM) and is selected from the group consisting of (C1-C10)-alkyl, (C1- C10)-alkylidene, (C1-C10)-alkylidyne, (C1-C10)-alkene, (C1-C10)-allyl, 1,3-butadiene, cyclobutadiene, cyclopentadienyl, cyclooctatetraene, 2,4,6-tris(trifluoromethyl )phenyl (Fmes), a mixture of any of these, and a mixture of these with halide anions, and p and q are any number from 1, 2, 3, 4, 5, 6, 7, 8, or 9. In this case, M it can be bound to ligands L of the same type (homoleptic cation) or of different types (heteroleptic cation). In an even more particular embodiment, B is selected from the group consisting of [Au(C6F5)Cl]-, [Au(C6F5)Br]-, [Au(C6F5)2]-, [Au(Fmes)2]- (where Fmes = 2,4,6-tris(trifluoromethyl)phenyl anion).

In another particular embodiment, B is a mixture of any of the aforementioned coordination complex anions, monatomic inorganic anions, polyatomic inorganic anions, organic anions, and/or organometallic anions.

In another particular embodiment, the cooling/heating process comprises a molecular organic-inorganic hybrid compound, where A is the trimethylsulfonium cation ([(CH3)3S]+).

In another particular embodiment, the cooling/heating process comprises a molecular organic-inorganic hybrid compound, where A is the 1-chloromethyltrimethylammonium cation ([(CH3)3(CH2Cl)N]+).

In another particular embodiment, the cooling/heating process comprises a molecular organic-inorganic hybrid compound, where A is the dibutylammonium cation ([(CH3CH2CH2CH2)2NH2]+).

In another particular embodiment, the cooling/heating process comprises a molecular organic-inorganic hybrid compound, where A is an organic cation selected from the group consisting of 1-chloro-methyl-triethylammonium ([(CH3CH2)3(CH2Cl) N]+), 1-chloro-methyl-tripropylammonium ([(CH3CH2CH2)3(CH2Cl)N]+), tetramethylammonium ([(CH3)4N]+).

In another particular embodiment, the cooling/heating process comprises a molecular organic-inorganic hybrid compound, where A is an organic cation selected from the group consisting of R1R2R3S+ where R1, R2 and R3 are one or more non-metallic chemical elements. .

In another particular embodiment, the cooling/heating process comprises a molecular organic-inorganic hybrid compound, where A is an organic cation selected from the group consisting of R1R2R3R4N+, where R1, R2, R3, and R4 are one or more elements non-metallic chemicals.

In another particular embodiment, the cooling/heating process comprises a molecular organic-inorganic hybrid compound, where A is an organic cation that is selected from the group consisting of R1R2R3R4P+, where Ri, R2. and R3 are one or more non-metallic chemical elements.

In another particular embodiment, the cooling/heating process comprises a molecular organic-inorganic hybrid compound, where A is an organic cation selected from the group consisting of R1R2R3S = O+, where R1, R2, and R3 are one or more elements. non-metallic chemicals.

In another particular embodiment, the refrigeration/heating process comprises a molecular organic-inorganic hybrid compound, where A is an organic cation that is selected from the group consisting of (C5-C10)-heterocyclic cations such as derivatives of Cuban, twistane, prismane, norbornane, basketane, oxazoline, tropane, imidazole, adamantane, thiophene, pyridine, piperidine, piperazine, etc.

In another particular embodiment, the cooling/heating process comprises a molecular organic-inorganic hybrid compound, where A is a homoleptic or heteroleptic organometallic cation of the general formula [MLq]p+, where M is selected from the group of transition metals, lanthanides, Al, Ga, Ge, In, Sn, Pb, Bi, or a mixture of these, L is an organic ligand that is chemically bonded to M via at least one carbon-metal (C-M) bond and is selected from the group consisting of Ligands (C rC 10)-alkyl, (C1-C10)-alkylidene, (C1-C10)-alkylidyne, (C1-C10)-alkene, (C1-C10)-allyl, 1,3-butadiene, cyclobutadiene, cyclopentadienyl , cyclooctatetraene, 2,4,6-tris(trifluoromethyl)phenyl (Fmes), a mixture of any of these, and a mixture of these with halide anions, and p and q are any number from 1, 2, 3, 4, 5, 6 , 7, 8 or 9.

In another particular embodiment, the cooling/heating process comprises a molecular organic-inorganic hybrid compound, where A is an organometallic cation with the general formula [MLq]p+, which is selected from the group consisting of cobalt (III) bis(cyclopentadienyl) ) ([Cp2Co]+) and iron(III) bis(cyclopentadienyl) ([Cp2Fe]+).

In another particular embodiment, the cooling/heating process comprises a molecular organic-inorganic hybrid compound, where A is a cation of a homoleptic or heteroleptic coordination complex of the general formula [ML1q]p+, where M is selected from the group consisting of cations of transition metals, lanthanides, Al, Ga, Ge, In, Sn, Pb, Bi, or a mixture thereof, L1 is selected from the group consisting of in ligands halide (F-, Cl", Br-, I"), sulfide (S2-), amino (NH3), aqua (H2O), bipyridyl (bpy), ethylenediamine (en), acetylacetonate (acac), oxalate ( ox), acetate (oac), cyanide (CN-), thiocyanate (NCS-), isothiocyanate (SCN-), and a mixture of these, and p and q are any number from 1, 2, 3, 4, 5, 6, 7 , 8 or 9.

In another particular embodiment, the cooling/heating process comprises a molecular organic-inorganic hybrid compound, where A is a coordination complex cation with the general formula [ML1q]p+, which is selected from the group consisting of [Co(NH3) 6]3+, [Co(NH3)5Cl]2+, [Co(NH3)4Cl2]+, and [Co(en)2Ch]+.

In another particular embodiment, the cooling/heating process comprises a molecular organic-inorganic hybrid compound, where A is a monatomic inorganic cation selected from the group consisting of Na+, K+, Cs+, Rb+, NH4+, Mg+2, Ca +2, Sr+2, Ba+2.

In another particular embodiment, the cooling/heating process comprises a molecular organic-inorganic hybrid compound, where A is a polyatomic inorganic cation that is selected from the group consisting of [NH4]+, [NF4]+, [N2H5E, and a mixture of these.

In another particular embodiment, the cooling/heating process comprises a molecular organic-inorganic hybrid compound, where A is a mixture of any of the aforementioned cations in any atomic proportion.

In another particular embodiment, the cooling/heating process comprises a molecular organic-inorganic hybrid compound, where B is a homoleptic or heteroleptic coordination complex anion of the general formula [ML1q]p-, where M is selected from the group consisting of transition metal cations, lanthanides, Al, Ga, Ge, In, Sn, Pb, Bi, or a mixture of these, L1 is selected from the group consisting of halide ligands (F-, Cl-, Br-, I- ), sulfur (S2-), amino (NH3), aqueous (H2O), bipyridyl (bpy), ethylenediamine (en), acetylacetonate (acac), oxalate (ox), acetate (oac), cyanide (CN-), thiocyanate (NCS-), isothiocyanate (SCN-), and a mixture of these, and p and q are any number from 1, 2, 3, 4, 5, 6, 7, 8, or 9.

In another particular embodiment, the cooling/heating process comprises a molecular organic-inorganic hybrid compound, where B is a complex anion of coordination of general formula [ML1q]p-, which is selected from the group consisting of [FeCU]-, [CoCU]', [GaCl4]-, [MnCU]2-, [FeBr4]-, [CoBr^, [GaBr4 ]-, [MnBr4]2-, [Au(CN)2]", [Ag(CN)2]-, [CoCl6]3-, [Co(NH3)Cl5]2-, and [Co(NH3)2Cl4 ]-.

In another particular embodiment, the cooling/heating process comprises a molecular organic-inorganic hybrid compound, where B is a monatomic inorganic anion selected from the group consisting of F-, Cl-, Br-, and I-.

In another particular embodiment, the cooling/heating process comprises a molecular organic-inorganic hybrid compound, where B is a polyatomic inorganic anion that is selected from the group consisting of [PF6]-, [BF4]-, [N(CN) 2]-, [H2PO2]-, [H2PO4]-, [HPO4]2-, [PO4]3-, [SO4]2-, [SCN]-, [CN]-, [N3]-, and a mixture of these.

In another particular embodiment, the cooling/heating process comprises a molecular organic-inorganic hybrid compound, where B is an organic anion selected from the group consisting of [HCOO]-, R1R2R3R4O-, O R 1R2R3R4O-, and R1R2R3S-( where R1, R2, R3, and R4 are one or more non-metallic elements).

In another particular embodiment, the cooling/heating process comprises a molecular organic-inorganic hybrid compound, where B is any heterocyclic organic anion.

In another particular embodiment, the cooling/heating process comprises a molecular organic-inorganic hybrid compound, where B is a homoleptic or heteroleptic organometallic anion of the general formula [MLq]p-, where M is selected from the group of transition metals, lanthanides , Al, Ga, Ge, In, Sn, Pb, Bi, or a mixture of these, L is an organic ligand that is chemically bonded to M via at least one carbon-metal (C-M) bond and is selected from the group consisting of in ligands (C1-C10)-alkyl, (C1-C10)-alkylidene, (C1-C10)-alkylidyne, (C1-C10)-alkene, (C1-C10)-allyl, 1,3-butadiene, cyclobutadiene, cyclopentadienyl, cyclooctatetraene, 2,4,6-tris(trifluoromethyl)phenyl (Fmes), a mixture of any of these, and a mixture of these with halide anions, and p and q are any number from 1, 2, 3, 4, 5, 6, 7, 8 or 9.

In another particular embodiment, the cooling/heating process comprises a molecular organic-inorganic hybrid compound, where B is an organometallic anion with the general formula [MLq]p-, which is selected from the group consisting of [Au(C6F5)Cl] -, [Au(C6F5)Br]", [Au(CaF5)2]-, and [Au(Fmes)2]" (where Fmes = 2,4,6-tris(trifluoromethyl)phenyl anion).

In another particular embodiment, the cooling/heating process comprises a molecular organic-inorganic hybrid compound, where B is a mixture of any of the aforementioned anions in any atomic proportion.

In a preferred embodiment, the cooling/heating process comprises the molecular organic-inorganic hybrid compound [(CH3)3S][FeCl4].

In another preferred embodiment, the cooling/heating process comprises an organic-inorganic hybrid compound that is selected from the group consisting of [Cp2Co][PF6] and [Cp2Fe][PF6].

In another preferred embodiment, the cooling/heating process comprises the molecular organic-inorganic hybrid compound [(CH3CH2CH2CH2)2NH2][BF4].

In another preferred embodiment, the cooling/heating process comprises the molecular organic-inorganic hybrid compound [(CH3)3(CH2Cl)N][FeCl4].

In another preferred embodiment, the cooling/heating process comprises an organic-inorganic hybrid compound that is selected from the group consisting of [(CH3)3(CH2Cl)N][GaCl4], [(CH3)3(CH2Cl)N] 2[MnCl4], [(CH3)3(CH2Cl)N][GaBr4], and [(CH3)3(CH2Cl)N][FeBr4].

In another preferred embodiment, the cooling/heating process comprises the molecular organic-inorganic hybrid compound [(CH3)4N][FeCl4].

In another preferred embodiment, the cooling/heating process comprises an organic-inorganic hybrid compound that is selected from the group consisting of [(CH3)3S][FeBr4], [(CH ^G a C U ], [(CH)3S ][GaBr4], [(CH^SMMnCU], [(CH3)3S]2[MnBr4], [(CH^SMCoBr^, and [(CH^SMCoCU].

In another preferred embodiment, the cooling/heating process comprises an organic-inorganic hybrid compound that is selected from the group consisting of [(CH3CH2)3(CH2Cl)N][FeCl4], and [(CH3CH2CH2)3(CH2Cl)N ][FeCl4].

In a particular embodiment, the cooling/heating process is carried out within a device by means of the cyclical and repetitive application of an external mechanical stimulus to the molecular organic-inorganic hybrid compound in a process that generally comprises the following steps:

a) apply an external stimulus with which the hybrid material is heated or cooled; b) maintaining the stimulus for a certain period of time in which the hybrid material releases or absorbs heat;

c) withdraw the stimulus so that the material cools or heats; Y

d) keeping the stimulus withdrawn for a period of time in which the hybrid material absorbs or releases heat.

By way of example, in a first step of said process, an external stimulus (such as hydrostatic pressure) is applied to the molecular organic-inorganic hybrid compound, which causes this material to heat up. In the second step, the applied external stimulus remains constant for a period of time so that the excess heat generated is transferred to a heat sink. This excess heat generated can be directed to the heat sink, either by direct contact of the hybrid material with said heat sink or by using a heat transfer fluid (such as air, water, alcohol, etc.). In the third step, once the molecular organic-inorganic hybrid compound has released that excess heat generated, the applied stimulus is withdrawn, which produces the cooling of said hybrid compound. In the fourth step, keeping the stimulus withdrawn for a certain time, the molecular organic-inorganic hybrid compound (which has been cooled in the previous step) absorbs the heat of the chamber (or space) that is intended to be cooled, for example, the interior of a fridge. Said heat is absorbed by direct contact of the hybrid material with this chamber or by using a heat transfer fluid (such as air, water, alcohol, etc.). This four-step process is repeated cyclically for a specific, predetermined period of time where the stimulus actuator (eg, a piston) automatically applies and removes pressure in an infinite cycle.

In a preferred embodiment, the cooling/heating process is one where the external stimulus is hydrostatic or uniaxial pressure. In a particular embodiment, the applied hydrostatic or uniaxial pressure is between 20 and 1500 bar (2-150 MPa). In a preferred embodiment, the applied hydrostatic/uniaxial pressure is between 20 and 1000 bar (2-100 MPa). In another more preferred embodiment, the applied hydrostatic/uniaxial pressure is between 20 and 800 bar (2-80 MPa). In a more preferred embodiment, the applied hydrostatic/uniaxial pressure is between 20 and 500 bar (2-50 MPa). In a more preferred embodiment, the applied hydrostatic/uniaxial pressure is between 20 and 200 bar (2-20 MPa).

In a particular embodiment, the molecular organic-inorganic hybrid compounds used in the refrigeration/heating process of the present invention allow working in an operational temperature range between -20 °C and 120 °C. In a more preferred embodiment, the operational temperature range is between -10°C and 90°C. In another more preferred embodiment, the operational temperature range is between 40 and 80 °C.

In a particular embodiment of the cooling/heating process, the molecular organic-inorganic hybrid compound is [(CH3)3S][FeCl4] and the operational temperature range is between 42 and 61 °C.

In a particular embodiment of the cooling/heating process, the molecular organic-inorganic hybrid compound is [(CH3)3(CH2Cl)N][FeCU] and the operational temperature range is between 53 and 67 °C.

In a particular embodiment of the cooling/heating process, the molecular organic-inorganic hybrid compound is [(CH3CH2CH2CH2)2NH2][BF4] and the operational temperature range is between -5 and 30 °C.

In addition, another aspect of the present invention is the use of molecular organic-inorganic hybrid materials of general formula AB (I), A2B (II) or AB2 (III) (as defined above) as heating materials for refrigeration/ heating. The particular and preferred embodiments of the cooling/heating process described above are also particular and preferred embodiments in this embodiment of the invention.

These materials can be incorporated into a cooling/heating device. The device can be used in different sectors such as the refrigeration/heating sector of air conditioning and heat pumps, refrigerators, electronic devices, automobiles, textiles, clothing, footwear, etc.

Therefore, another aspect of the present invention comprises a cooling/heating device whose cooling capacity is generated by an external stimulus. Said device comprises:

(I) a molecular organic-inorganic hybrid compound of the general formula AB(I), A2B(II) or AB2(III); (2) means for cyclically applying and removing a mechanical stimulus on said molecular organic-inorganic hybrid compound for a certain period of time, wherein the mechanical stimulus is selected from the group consisting of hydrostatic pressure, uniaxial pressure, and uniaxial tension.

In a particular embodiment, the device of the invention comprises means to apply hydrostatic pressure as an external stimulus. In another particular embodiment, the device of the invention comprises means for applying uniaxial pressure and/or tension. The particular and preferred values of hydrostatic pressure, uniaxial pressure and uniaxial stress defined above for the cooling/heating process are also particular/preferred values for the device media.

In a particular embodiment, the means for the cyclical application and withdrawal of an external mechanical stimulus selected between hydrostatic pressure and uniaxial pressure can be the following: a piston, a liquid or the hand or finger of a person on a screen (or any actuator exerting hydrostatic or uniaxial pressure).

In another particular embodiment, the device of the invention further comprises:

(3) a heat sink that is responsible for dissipating heat to the outside;

(4) optionally a heat exchange fluid; Y

(5) a chamber or space that needs to be cooled.

The heat sink could be, for example, a fan, a radiator, etc. The heat exchanger fluid is optional and, if present, could be selected from among air, water, alcohols, oils, etc. By way of example, in the case of a refrigerator, the chamber or space that needs to be cooled would be the interior chamber of said refrigerator. As another example, in the case of a smartphone, the space that would need to be cooled would be the inside of the phone. In another example, in the case of shoes, the deposit would be the inside of the shoes.

Furthermore, in the cooling device, the molecular organic-inorganic hybrid compound can be used in the form of a powder, suspended in a fluid (or in a solid matrix) that acts as a heat exchanger and/or improves thermal conductivity, or as a thin film (thin layer), for example, on screens for electronic devices.

Thus, in a particular embodiment of the device, the molecular organic-inorganic hybrid compound with the general formula AB (I), A2B (II) or AB2 (III) is in powder form, suspended in a heat exchanger liquid (oil, silicone, water). , alcohols, etc.), suspended in a solid heat exchanger matrix (for example, a matrix of a polymer, metal alloy, or steel), or in the form of a thin film on top of a heat-conducting substrate (for example, a sheet of glass or metal).

A particular embodiment of the present invention comprises a molecular organic-inorganic hybrid compound of formula [(CH3)3S][FeCl4 ] (that is, a compound of formula AB, where A is the trimethylsulfonium cation [(CH3ESI+) and B is the anion iron(iii) tetrachloride ([FeCL]-)) This compound has the crystalline structure obtained by single crystal X-ray diffraction illustrated in Fig. 3.

Another particular embodiment of the present invention comprises a molecular organic-inorganic hybrid compound of formula [(CH3)3(CH2Cl)N][FeCl4] (that is, a compound of formula AB, where A is the 1-chloromethyltrimethylammonium cation ([ (CH3)3(CH2Cl)N]+) and B is the iron(iii) tetrachloride anion ([FeCU]")). This compound has the crystalline structure obtained by single crystal X-ray diffraction illustrated in FIG. 4 .

Also part of the present invention is a molecular organic-inorganic hybrid compound of formula [(CH3CH2CH2CH2)2NH2][BF4] (i.e., a compound of formula AB, where A is the dibutylammonium cation ([(CH3CH2CH2CH2)2NH2]+) and B is the tetrafluoroborate anion ([BF4]-).

The crystal structure of the molecular organic-inorganic hybrid compounds of the present invention was obtained by single crystal X-ray. For this, samples of said materials were selected to collect diffraction data at room temperature in a Bruker Kappa diffractometer equipped with a CCD detector. APEX II and with monochromatic MoKa radiation (A = 0.71073 Á). Crystals were mounted on a MiTeGen MicroMountTM using Paratone® (Chevron Corporation). To carry out these experiments, the crystals were measured at room temperature. Data collection, integration, and reduction were performed using the APEX2 V2015.9-0 software package (Bruker AXS, 2015), which includes the programs detailed below. Intensity integration was performed with SAINT 8.34A and corrected for Lorentz and polarization effects and also for absorption by multiple scanning methods based on equivalent symmetries data using SADABS 2008/1 or TWINABS 2012/1, depending on the presence or absence of twins. For each of the measured crystals, a unique and distinct lattice was found at room temperature (T = 25 °C).

The structures were solved by direct methods using the SHELXT2014 program and refined by the method of least squares in SHELXL2014/7. To refine the structures, anisotropic thermal factors for all non-H atoms were taken into account. The hydrogen atoms of the cations could not be found in the Fourier map due to the structural disorder of these cations. All hydrogen atoms were refined with the driving model implemented in SHELXL2014/7.

As an example, single crystal X-ray diffraction at room temperature reveals that the compound [(CH3)3S][FeCl4] has an orthorhombic crystal structure with the following cell parameters a = 12.7238(8) Á, b = 7.8934 (5) Á, c = 11.5483(7) Á, and presents the atomic distances indicated in Table 1.

Table 1: Selected atomic distances for the compound [(CH3)3S][FeCl4] at room temperature.

As a further example, single crystal X-ray diffraction at room temperature reveals that the compound [(CH3)3(CH2Cl)N][FeCl4] has an orthorhombic crystal structure with the following cell parameters a = 12.7238(8) Á, b = 7.8934(5) Á, c = 11.5483(7) Á, and shows the atomic distances indicated in Table 2.

Table 2: Selected atomic distances for the compound [(CH3)3(CH2Cl)N][FeCl4] at room temperature.

The molecular organic-inorganic hybrid compounds of the present invention remain thermally stable at least up to 175°C, and in some cases up to 500°C. The thermal stability of these compounds is similar to, or even greater than, that of the comparative caloric compounds of [(CH3CH2CH2)4N]Mn[N(CN)2]3 and [(CH3)2NH2]PbCl3 previously described. Furthermore, most of the compounds of the present invention remain stable under ambient conditions of temperature, light, and 65% relative humidity for at least several weeks.

Throughout the description and claims the word "comprises" and its variants are not intended to exclude other technical characteristics, additives, components or steps. In addition, the word "comprises" includes the case "consists of". For those skilled in the art, other objects, advantages, and features of the invention will emerge in part from the description and in part from the practice of the invention. The following examples and drawings are provided by way of illustration, and are not intended to be limiting. of the present invention. Furthermore, the present invention covers all possible combinations of particular and preferred embodiments indicated herein.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1: Crystal structure of the comparative compound [(CH3CH2CH2)4N]Mn[N(CN)2]3 obtained by single crystal X-ray diffraction.

FIG. 2: Crystal structure of the comparative compound [(CH3)2NH21PbCh obtained by single crystal X-ray diffraction.

FIG. 3: Crystal structure of the compound [(CH3)3S1[FeCL1 obtained by single crystal X-ray diffraction.

FIG. 4: Crystal structure of the compound [(CH3)3(CH2Cl)N1[FeCL1 obtained by single crystal X-ray diffraction.

FIG. 5: Isothermal entropy change of the compound [(CH3)3S][FeCL].

FIG. 6: Isothermal change of entropy of the compound [(CH3)3(CH2Cl)N1[FeCL1.

EXAMPLES

All the examples presented here were obtained by similar synthetic methods. The synthetic method used for the examples [(CH3)3S][FeCl4] and [(CH3)3(CH2Cl)N][FeCl4] is explained in more detail below:

Example 1: Preparation of materials [(CH3)3(CH2Cl)N1n[MX4l:

The materials [(CH3)3(CH2Cl)N]n[MX4] (where M = Fe3+, Ga3+ or Mn2+, X = Cl" or Br-, n = 1 or 2) were obtained by crystallization from an aqueous solution. To obtain the precursor [(CH3)3(CH2Cl)N]Cl, stoichiometric amounts of dichloromethane (98% Sigma-Aldrich) and trimethylamine (45% by weight aqueous solution, Sigma-Aldrich) were mixed. the precursor, F e C h ^^O (98% Sigma-Aldrich), GaCh (99% Scharlab) or MnCE4H2O (99% Sigma-Aldrich) were mixed stoichiometrically in 3 mL of water and 3 mL of HCl ( about 37 % in H2O, ACROS Organics) or HBr (48 wt. % in Sigma-Aldrich H2O). The desired compound was instantly obtained as a polycrystalline powder. Subsequently, the material was recrystallized for 3 days in a mixture of acetone:water (1:1) to obtain yellow-brown crystals when M = Fe3+ or transparent when M = Ga3+ or Mn2+.

Example 2: Preparation of [(CH3)3S1[MX4l

The materials [(CH3)3S]n[MX4] (where M = Fe3+, Ga3+, Mn2+ or Co2+, X = Cl- or Br-, and n = 1 or 2) were obtained by crystallization from an aqueous solution. The reagent [(CH3)3S]Br (98% Sigma-Aldrich) was mixed stoichiometrically with FeCE6 H2O (98% Sigma-Aldrich), GaCh (99% Scharlab), MnCE4 H2O (99% Sigma-Aldrich), or CoCE6 H2O ( 98% Sigma-Aldrich) in 3 mL of water and 3 mL of HCl (ca. 37% in H2O, ACROS Organics) or HBr (48 wt.% in Sigma-Aldrich H2O) was added. The desired compound was instantly obtained as a polycrystalline powder. Subsequently, the material was recrystallized for 3 days in a mixture of acetone:water (1:1) to obtain yellow-brown crystals when M = Fe3+, blue when M = Co2+ or transparent when M = Ga3+ or Mn2+.

Example 3: Determination of the barocaloric effect

The thermal properties of the materials described here were studied by differential scanning calorimetry. In this way, around 100 mg of sample of the different materials were analyzed in a Setaram Setaram p-DSC evo7 calorimeter equipped with a pressure cell. The samples were cyclically heated and cooled from -20 °C to 120 oC, at a rate between 1 oC min-1 and 1.2 °C min-1, and under a nitrogen atmosphere. These heating and cooling cycles were carried out at different nitrogen pressures from 1 bar to 1200 bar. Table 3 shows the thermal and caloric parameters obtained.

Table 3: Thermal and caloric parameters obtained for the different hybrid materials.

Table notes: AS is the entropy change of the transition, AH is the latent heat, T is the transition temperature, Top is the operational temperature range of barocaloric effects obtained under 1000 bar pressures, dTt/dp is the dependence of transition temperature on pressure. *For Example 2, the operational range of temperature was taken at 800 bar. **Estimated values by comparison with similar materials.

The reversible isothermal entropy change of Example 1 and 2 is shown in FIGS.

5 and 6, respectively.

The barocaloric effect (in terms of isothermal entropy change) of the compounds of this invention are considerably larger than that of Comparative Examples 1-3. In addition, the compounds of the present invention also have a better operational temperature range than the comparative compounds, which extends the range in which these materials can work.

LIST OF APPOINTMENTS

patent literature

- W. Li et al., patent CN107418517B

- J. M. Bermúdez-García et al., patent WO2019081799A1

Non-patent literature

- Regulation EU No 517/2014

- X. Moya et al., Nature Materials, 2014, 13, 439-450

- J. M. Bermúdez-García et al., Nat. Commun., 2017, 8, 15715

- J.M. Bermúdez-García et al. J. Mater. Chem. C, 2018, 6 (37), 9867-9874

- M. Szafranski et al. APL Materials 2018, 6, 100701

- J. Salgado-Beceiro et al. Materials Advances, 2020, 1, 3167-3170

- J. M. Bermúdez-García et al., J. Phys. Chem. Lett., 2017, 8, 4419-4423

Claims (20)

1. Cooling/heating process that comprises the application of an external stimulus selected from the group consisting of hydrostatic pressure, uniaxial pressure, and uniaxial stress, to a molecular organic-inorganic hybrid compound of the general formula: AB(I), A2B(II) or AB2(III) where: the molecular organic-inorganic hybrid compound comprises inorganic ions and organic ions; A is selected from the group consisting of an organic cation, an organometallic cation, a mixture of organic and organometallic cations, a coordination complex cation, a monatomic inorganic cation, a polyatomic inorganic cation, and a mixture of any of the above in any atomic ratio; and B is selected from the group consisting of a coordination complex anion, a monatomic inorganic anion, a polyatomic inorganic anion, an organic anion, an organometallic anion, and a mixture of any of the foregoing in any atomic ratio; when A is an organic cation, it is selected from the group consisting of trimethylsulfonium ([(CH3)3S]+), 1-chloro-methyl-trimethylammonium ([(CH3)3(CH2Cl)N]+), 1-chloro- methyl-triethylammonium ([(CH3CH2)3(CH2Cl)N]+), 1-chloro-methyl-tripropylammonium ([(CH3CH2CH2)3(CH2Cl)N]+), tetramethylammonium ([(CH3ENE), dibutylammonium ([(CH3CH2CH2CH2ENH2D R1R2R3R4N+, R1R2R3R4P+, R1R2R3S+, and R1R2R3S; when A is an organometallic cation, it is selected from the group consisting of cations of the general formula [MLq]p+, where M is bound to either ligands L of the same or different types; when A is a mixture of organic and organometallic cations, said mixture comprises any of the aforementioned organic and organometallic cations in any atomic ratio; when A is a coordination complex cation, it is selected from the group consisting of cations of the general formula [ML1q]p+, where M is bound to either L1 ligands of the same or different types; when A is a monatomic inorganic cation, it is selected from the group consisting of Na+, K+, Cs+, Rb+, Mg2+, Ca2+, Sr2+, and Ba2+; when A is a polyatomic inorganic cation, it is selected from the group consisting of [NH]+, [NF4]+, [N2H5]+, and a mixture thereof; when A is a mixture of cations, said mixture comprises any of the aforementioned organic cations, organometallic cations, coordination complex cations, monatomic inorganic cations and/or polyatomic inorganic cations, in any atomic ratio; When B is a coordination complex anion, is selected from the group consisting of anions of the general formula [ML1q]p-, M is bound to either L1 ligands of the same or different types; when B is a monatomic inorganic anion, it is selected from the group consisting of F-, Cl-, Br-, and I-; when B is a polyatomic inorganic anion, it is selected from the group consisting of is selected from the group consisting of [PF6]-, [BF4]-, [N(CN)2]-, [H2PO2]-, [H2PO4] -, [HPO4]2-, [PO4]3-, [SO4]2-, [SCN]-, [CN]-, [N3]-, and a mixture thereof; when B is an organic anion, it is selected from the group consisting of [HCOO]-, R1R2R3R4O-, -OR1R2R3R4O-, and R1R2R3S-; when B is an organometallic anion, it is selected from the group consisting of anions of the general formula [MLq]p-, where M is bound to either ligands L of the same or different types; when B is a mixture of anions, said mixture comprises any of the aforementioned coordination complex anions, monatomic inorganic anions, polyatomic inorganic anions, organic anions and/or organometallic anions, mentioned above in any atomic ratio; where: R1, R2, R3, and R4 are independently selected from the group consisting of non-metallic elements, and (C5-C10)-heterocyclic cations; non-metallic elements are elements of the periodic table that are not metals; M is independently selected from the group consisting of transition metals, lanthanides, Al, Ga, Ge, In, Sn, Pb, Bi, and a mixture of these, L is an organic ligand that is chemically bonded to M via at least one carbon-metal (C-M) bond, which is independently selected from the group consisting of (C1-C10)-alkyl, (C1-C10)-alkylidene, ( C1-C10)- (C1-C10)-alkylidyne, (C1-C10)-alkene, (C1-C10)-allyl, 1,3-butadiene, cyclobutadiene, cyclopentadienyl, cyclooctatetraene, 2,4,6-tris(trifluoromethyl )phenyl (Fmes), a mixture of any of these, and a mixture of these with halide anions, L1 is independently selected from the group consisting of halide, sulfide (S2-), amino (NH3), aqua (H2O), bipyridyl (bpy), ethylenediamine (en), acetylacetonate (acac), oxalate (ox), acetate ( oac), cyanide (CN-), thiocyanate (NCS-), isothiocyanate (SCN-), and a mixture thereof; the halide ligands are F-, Cl-, Br- and I-; Y p and q are independently an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, and 9. 2. Refrigeration/heating process according to claim 1, wherein the organic-inorganic hybrid material is the compound [(CH3)3S][FeCl4]. 3. Refrigeration/heating process according to claim 1, wherein the organic-inorganic hybrid material is the compound [(CH3)3(CH2Cl)N][FeCl4]. The cooling/heating process according to claim 1, wherein the organic-inorganic hybrid material is a compound selected from the group consisting of [Cp2Co][PF6] and [Cp2Fe][PF6]. 5. Refrigeration/heating process according to claim 1, wherein the organic-inorganic hybrid material is the compound [(CH3CH2CH2CH2ENH2HBF4]. 6. Cooling/heating process according to claim 1, wherein the organic-inorganic hybrid material is a compound selected from the group consisting of [(CH3)3(CH2Cl)N][GaCl4], [(CH3)3(CH2Cl) N]2[MnCl4], [(CH3)3(CH2Cl)N][GaBr4] and [(CH3)3(CH2Cl)N][FeBr4]. 7. Refrigeration/heating process according to claim 1, wherein the organic-inorganic hybrid material is the compound [(CH3)4N][FeCl4]. 8. Cooling/heating process according to claim 1, wherein the organic-inorganic hybrid material is a compound selected from the group consisting of [(CH3)3S][FeBr4], [(CH ^ G a C U ], [(CH3 )3S][GaBr4], [(CH^S^MnCU], [(CH3)3S]2[MnBr4], [(CH^SMCoBr^, and [(CH^SMCoCU]. 9. The cooling/heating process according to claim 1, wherein the organic-inorganic hybrid material is a compound selected from the group consisting of [(CH3CH2)3(CH2Cl)N][FeCl4] and [(CH3CH2CH2)3(CH2Cl) N][FeCl4]. 10. Cooling/heating process according to any of claims 1-9, wherein the external stimulus is hydrostatic pressure. 11. Cooling/heating process according to any of claims 1-10, where said process is cyclical and continuous, and where each cycle also comprises: a) applying and maintaining the external stimulus for a determined period of time, during which the hybrid material either releases or absorbs heat that is conducted to the exterior or absorbed from the interior of the device respectively; b) withdrawal of the stimulus for a determined period of time, during which the hybrid material either cools or heats up and the cooling/heating cycle is completed; 12. Use of a molecular organic-inorganic hybrid material of general formula AB (I), A2B (II) and/or AB2 (III), as defined in any of claims 1-9, as a caloric material for cooling/heating devices. 13. Device with cooling/heating capacity induced by an external stimulus comprising: a) a molecular organic-inorganic hybrid material of general formula AB (I), A2B (II) and/or AB2 (III), as defined in any of claims 1-9; b) means for applying/removing the stimulus on said hybrid material for a determined period of time, where the external stimulus is selected from the group consisting of hydrostatic pressure, uniaxial pressure, and uniaxial tension. Device according to claim 13, wherein the molecular organic-inorganic hybrid material is in the form of a powder, suspended in a fluid, suspended in a solid matrix, or in the form of a thin sheet. 15. An organic-inorganic hybrid material selected from the group consisting of [(CH3)3(CH2Cl)N][GaCl4], [(CH3)3(CH2Cl)N][GaBr4, and [(CHMC^CONMMnCU]. 16. Process for preparing an organic-inorganic hybrid material selected from the group consisting of [(CH3)3(CH2Cl)N][GaCl4], [(CH3)3(CH2Cl)N][GaBr4] and [(CH3) 3(CH2Cl)N]2[MnCl4] which comprises carrying out a mixed reaction of solutions of the salts [(CH3)3(CH2Cl)N]Cl and MX3 (M = Ga3+, Mn2+; X = Cl-, B r) 17. Process according to claim 16, wherein the mixture of solutions of the salts is carried out with stoichiometric amounts of [(CH3)3(CH2Cl)N]Cl and MX3 (M = Ga3+, Mn2+; X = Cl- , Br-). 18. An organic-inorganic hybrid material selected from the group consisting of [(CH3)3S][FeBr4], [(CH3)3S][GaCl4], [(CH3)3S][GaBr4], [(CH^S^MnCU ], [(CH3)3S]2[CoBr4], and [(CH3)3S]2[CoCl4]. 19. Process for preparing an organic-inorganic hybrid material selected from the group consisting of [(CH3)3S][FeBr4], [(CH3)3S][GaCl4], [(CH3)3S][GaBr4], [( CH^S^MnCU], [(CH3)3S]2[CoBr4], and [(CH3)3S]2[CoCl4] which comprises carrying out a reaction of mixing solutions of the salts [(CH3)3S]Cl , and MX3 (M = Fe3+, Ga3+, Co2+, Mn2+; X = Cl- , Br-). 20. Process according to claim 19, where the mixture of salt solutions is carried out with stoichiometric amounts of [(CH3)3S]Cl and MX3 (M = Fe3+, Ga3+, Co2+, Mn2+; X = Cl-, Br -).