WO2014025424A2

WO2014025424A2 - Boron-nitrogen-containing acene compounds and their preparation

Info

Publication number: WO2014025424A2
Application number: PCT/US2013/040367
Authority: WO
Inventors: Shih-Yuan Liu; Jonathan Marshall
Original assignee: State Of Oregon Acting By & Through The State Board Of Higher Educ. On Behalf Of The Univ. Of Oregon
Priority date: 2012-05-10
Filing date: 2013-05-09
Publication date: 2014-02-13
Also published as: WO2014025424A3

Abstract

A method for detecting thermal and fast neutron emission that includes placing a boron- nitrogen polycyclic material in an environment for detecting possible neutron emission, wherein the detection can discriminate between neutron emission and gamma-ray emission.

Description

BORON-NITROGEN-CONTAINING ACENE COMPOUNDS AND THEIR

PREPARATION

This application claims the benefit of U.S. Provisional Application No. 61/645,445, filed May 10, 2012, which is incorporated herein by reference in its entirety.

BACKGROUND

The ability to detect low-level high-energy neutrons in a strong gamma ray background is of major importance for nuclear nonproliferation and for the detection of illicit nuclear materials since fast neutrons are strongly suggestive of the presence of fissile material such as plutonium and highly-enriched uranium. Providing the capabilities to reduce, eliminate, and counter the threat of nuclear proliferation is of great importance. One way to passively determine the presence of nuclear weapons is to detect and identify the characteristic neutron signature of high enriched uranium and weapons grade plutonium.

SUMMARY

Disclosed herein is a method for detecting thermal and fast neutron emission comprising; placing a boron-nitrogen polycyclic material in an environment for detecting possible thermal and fast neutron emission, wherein the detection can discriminate between neutron emission and gamma-ray emission.

Also disclosed herein is a method for detecting the presence of a nuclear material, comprising:

providing a boron-nitrogen polycyclic material for detecting possible thermal and fast neutron emission from a nuclear material, wherein the detection can discriminate between neutron emission and gamma-ray emission.

Further disclosed herein is a compound having a structure of:

Formula 1 wherein R 1 and R 2 are each individually selected from H, optionally substituted alkyl, optionally substituted aryl, optionally substituted alkoxy, acyl, acyloxy, alkoxycarbonyl, amino, aminocarbonyl, aryloxy, carboxyl, optionally substituted cycloalkyl, halogen, or hydroxyl; and A has a structure of:

Formula 3 wherein ring B is fused to the boron-nitrogen ring of Formula 1, rings B and C are each aromatic rings; X¹, X², X³ and X⁴ are each C, or X¹ is B, X² is N, and X³ and X⁴ are each C, or X³ is B, X⁴ is N, and X¹ and X² are each C; and R⁵, R⁶, R⁷, R⁸, R⁹ and R¹⁰ are each individually selected from H, optionally substituted alkyl, optionally substituted aryl, optionally substituted alkoxy, acyl, acyloxy, alkoxycarbonyl, amino, aminocarbonyl, aryloxy, carboxyl, optionally substituted cycloalkyl, halogen, or hydroxyl, provided that the compound is not:

Additionally disclosed herein is a compound having a structure of:

Formula 2 wherein each of R³ and R⁴ are each individually selected from H, optionally substituted alkyl, optionally substituted aryl, optionally substituted alkoxy, acyl, acyloxy, alkoxycarbonyl, amino, aminocarbonyl, aryloxy, carboxyl, optionally substituted cycloalkyl, halogen, or hydroxyl, provided that at least one of R³ or R⁴ is a fused polycyclic aromatic moiety, and provided that the compound is not:

Also disclosed herein is a compound having a structure of:

Formula IA

wherein R 1 and R 2 are each individually selected from H, optionally substituted alkyl, optionally substituted aryl, optionally substituted alkoxy, acyl, acyloxy, alkoxycarbonyl, amino, aminocarbonyl, aryloxy, carboxyl, optionally substituted cycloalkyl, halogen, or hydroxyl;

20 and R 21 are each individually selected from H, optionally substituted alkyl, optionally substituted aryl, optionally substituted alkoxy, acyl, acyloxy, alkoxycarbonyl, amino,

aminocarbonyl, aryloxy, carboxyl, optionally substituted cycloalkyl, halogen, or hydroxyl, provided that at least one of R 20 and R 21 is not H; and A has a structure of:

Formula 3 wherein ring B is fused to the boron-nitrogen ring of Formula 1, rings B and C are each aromatic rings; X¹, X², X³ and X⁴ are each C, or X¹ is B, X² is N, and X³ and X⁴ are each C, or X³ is B, X⁴ is N, and X¹ and X² are each C; and R⁵, R⁶, R⁷, R⁸, R⁹ and R¹⁰ are each individually selected from H, optionally substituted alkyl, optionally substituted aryl, optionally substituted alkoxy, acyl, acyloxy, alkoxycarbonyl, amino, aminocarbonyl, aryloxy, carboxyl, optionally substituted cycloalkyl, halogen, or hydroxyl.

The foregoing will become more apparent from the following detailed description, which proceeds with reference to the accompanying figures. BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 show illustrative compounds as disclosed herein.

FIGS. 3-6 show various synthetic schemes.

FIGS. 7A-7F are graphs reporting various properties of a N-H B-phenyl naphthalene compound (FIG. 2, third compound).

FIG. 8 is an alternative synthesis for 1,2-BN-anthracene.

FIG. 9 shows a synthesis scheme for anti-BN-anthracene.

FIG. 10 shows a synthesis for phenyl-substituted syn-BN-anthracene.

FIG. 11 shows a proposed synthesis for syn-BN-anthracene.

FIGS. 12 and 13 are graphs reporting properties of several compounds.

DETAILED DESCRIPTION

Terminology

The following explanations of terms and methods are provided to better describe the present compounds, compositions and methods, and to guide those of ordinary skill in the art in the practice of the present disclosure. It is also to be understood that the terminology used in the disclosure is for the purpose of describing particular embodiments and examples only and is not intended to be limiting.

An "R-group" or "substituent" refers to a single atom (for example, a halogen atom) or a group of two or more atoms that are covalently bonded to each other, which are covalently bonded to an atom or atoms in a molecule to satisfy the valency requirements of the atom or atoms of the molecule, typically in place of a hydrogen atom. Examples of R-groups/substituents include alkyl groups, hydroxyl groups, alkoxy groups, acyloxy groups, mercapto groups, and aryl groups.

"Substituted" or "substitution" refer to replacement of a hydrogen atom of a molecule or an R-group with one or more additional R-groups such as halogen, alkyl, alkoxy, alkylthio, trifluoromethyl, acyloxy, hydroxy, mercapto, carboxy, aryloxy, aryl, arylalkyl, heteroaryl, amino, alkylamino, dialkylamino, morpholino, piperidino, pyrrolidin-l-yl, piperazin-l-yl, nitro, sulfato or other R-groups. "Acyl" refers to a group having the structure -C(0)R, where R may be, for example, optionally substituted alkyl, optionally substituted aryl, or optionally substituted heteroaryl.

"Lower acyl" groups are those that contain one to six carbon atoms.

"Acyloxy" refers to a group having the structure -OC(0)R-, where R may be, for example, optionally substituted alkyl, optionally substituted aryl, or optionally substituted heteroaryl.

"Lower acyloxy" groups contain one to six carbon atoms.

"Alkenyl" refers to a cyclic, branched or straight chain group containing only carbon and hydrogen, and unless otherwise mentioned typically contains one to twelve carbon atoms, and contains one or more double bonds that may or may not be conjugated. Alkenyl groups may be unsubstituted or substituted. "Lower alkenyl" groups contain one to six carbon atoms.

The term "alkoxy" refers to a straight, branched or cyclic hydrocarbon configuration and combinations thereof, including from 1 to 20 carbon atoms, preferably from 1 to 8 carbon atoms (referred to as a "lower alkoxy"), more preferably from 1 to 4 carbon atoms, that include an oxygen atom at the point of attachment. An example of an "alkoxy group" is represented by the formula - OR, where R can be an alkyl group, optionally substituted with an alkenyl, alkynyl, aryl, aralkyl, cycloalkyl, halogenated alkyl, alkoxy or heterocycloalkyl group. Suitable alkoxy groups include methoxy, ethoxy, n-propoxy, i-propoxy, n-butoxy, i-butoxy, sec-butoxy, tert-butoxy cyclopropoxy, cyclohexyloxy, and the like.

"Alkoxycarbonyl" refers to an alkoxy substituted carbonyl radical, -C(0)OR, wherein R represents an optionally substituted alkyl, aryl, aralkyl, cycloalkyl, cycloalkylalkyl or similar moiety.

The term "alkyl" refers to a branched or unbranched saturated hydrocarbon group of 1 to 24 carbon atoms, such as methyl, ethyl, w-propyl, isopropyl, w-butyl, isobutyl, i-butyl, pentyl, hexyl, heptyl, octyl, decyl, tetradecyl, hexadecyl, eicosyl, tetracosyl and the like. A "lower alkyl" group is a saturated branched or unbranched hydrocarbon having from 1 to 6 carbon atoms. Preferred alkyl groups have 1 to 4 carbon atoms. Alkyl groups may be "substituted alkyls" wherein one or more hydrogen atoms are substituted with a substituent such as halogen, cycloalkyl, alkoxy, amino, hydroxyl, aryl, alkenyl, or carboxyl. For example, a lower alkyl or (C₁-C₆)alkyl can be methyl, ethyl, propyl, isopropyl, butyl, iso-butyl, sec-butyl, pentyl, 3-pentyl, or hexyl; (C₃-C₆)cycloalkyl can be cyclopropyl, cyclobutyl, cyclopentyl, or cyclohexyl; (C₃-C₆)cycloalkyl(C₁-C₆)alkyl can be cyclopropylmethyl, cyclobutylmethyl, cyclopentylmethyl, cyclohexylmethyl, 2-cyclopropylethyl, 2-cyclobutylethyl, 2-cyclopentylethyl, or 2-cyclohexylethyl; (C₁-C₆)alkoxy can be methoxy, ethoxy, propoxy, isopropoxy, butoxy, iso-butoxy, sec-butoxy, pentoxy, 3-pentoxy, or hexyloxy; (C₂-C₆)alkenyl can be vinyl, allyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1,- pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1- hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl, or 5- hexenyl; (C₂-C₆)alkynyl can be ethynyl, 1-propynyl, 2-propynyl, 1-butynyl, 2-butynyl, 3-butynyl, 1-pentynyl, 2-pentynyl, 3-pentynyl, 4-pentynyl, 1- hexynyl, 2-hexynyl, 3-hexynyl, 4-hexynyl, or 5- hexynyl; (Ci-C₆)alkanoyl can be acetyl, propanoyl or butanoyl; halo(C₁-C₆)alkyl can be

iodomethyl, bromomethyl, chloromethyl, fluoromethyl, trifluoromethyl, 2-chloroethyl, 2- fluoroethyl, 2,2,2-trifluoroethyl, or pentafluoroethyl; hydroxy(C₁-C₆)alkyl can be hydroxymethyl, 1-hydroxyethyl, 2-hydroxyethyl, 1-hydroxypropyl, 2-hydroxypropyl, 3-hydroxypropyl, 1- hydroxybutyl, 4-hydroxybutyl, 1-hydroxypentyl, 5-hydroxypentyl, 1 -hydroxyhexyl, or 6- hydroxyhexyl; (C₁-C₆)alkoxycarbonyl can be methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, isopropoxycarbonyl, butoxycarbonyl, pentoxycarbonyl, or hexyloxycarbonyl; (C₁-C₆)alkylthio can be methylthio, ethylthio, propylthio, isopropylthio, butylthio, isobutylthio, pentylthio, or hexylthio; (C₂-C₆)alkanoyloxy can be acetoxy, propanoyloxy, butanoyloxy, isobutanoyloxy, pentanoyloxy, or hexanoyloxy.

"Alkynyl" refers to a cyclic, branched or straight chain group containing only carbon and hydrogen, and unless otherwise mentioned typically contains one to twelve carbon atoms, and contains one or more triple bonds. Alkynyl groups may be unsubstituted or substituted. "Lower alkynyl" groups are those that contain one to six carbon atoms.

The term "amine" or "amino" refers to a group of the formula -NRR', where R and R' can be, independently, hydrogen or an alkyl, alkenyl, alkynyl, aryl, aralkyl, cycloalkyl, halogenated alkyl, or heterocycloalkyl group. For example, an "alkylamino" or "alkylated amino" refers to - NRR', wherein at least one of R or R' is an alkyl.

"Aminocarbonyl" alone or in combination, means an amino substituted carbonyl

(carbamoyl) radical, wherein the amino radical may optionally be mono- or di-substituted, such as with alkyl, aryl, aralkyl, cycloalkyl, cycloalkylalkyl, alkanoyl, alkoxycarbonyl, aralkoxycarbonyl and the like. An aminocarbonyl group may be -N(R)-C(0)-R (wherein R is a substituted group or H). A suitable aminocarbonyl group is acetamido. The term "amide" or "amido" is represented by the formula -C(0)NRR', where R and R' independently can be a hydrogen, alkyl, alkenyl, alkynyl, aryl, aralkyl, cycloalkyl, halogenated alkyl, or heterocycloalkyl group described above.

"Aryl" refers to a monovalent unsaturated aromatic carbocyclic group having a single ring (e.g., phenyl) or multiple condensed rings (e.g., naphthyl or anthryl), which can optionally be unsubstituted or substituted. A "heteroaryl group," is defined as an aromatic group that has at least one heteroatom incorporated within the ring of the aromatic group. Examples of heteroatoms include, but are not limited to, nitrogen, oxygen, sulfur, and phosphorous. Heteroaryl includes, but is not limited to, pyridinyl, pyrazinyl, pyrimidinyl, pyrrolyl, pyrazolyl, imidazolyl, thiazolyl, oxazolyl, isooxazolyl, thiadiazolyl, oxadiazolyl, thiophenyl, furanyl, quinolinyl, isoquinolinyl, benzimidazolyl, benzooxazolyl, quinoxalinyl, and the like. The aryl or heteroaryl group can be substituted with one or more groups including, but not limited to, alkyl, alkynyl, alkenyl, aryl, halide, nitro, amino, ester, ketone, aldehyde, hydroxy, carboxylic acid, or alkoxy, or the aryl or heteroaryl group can be unsubstituted.

"Aryloxy" or "heteroaryloxy" refers to a group of the formula -OAr, wherein Ar is an aryl group or a heteroaryl group, respectively.

The term "carboxylate" or "carboxyl" refers to the group -COO^" or -COOH.

The term "ester" refers to a carboxyl group having the hydrogen replaced with, for example a Ci-₆alkyl group ("carboxylCi-ealkyl" or "alkylester"), an aryl or aralkyl group ("arylester" or "aralkylester") and so on. CO^i-salkyl groups are preferred, such as for example, methylester (CO ₂Me), ethylester (C0₂Et) and propylester (C0₂Pr) and includes reverse esters thereof (e.g. - OCOMe, -OCOEt and -OCOPr).

The term "cycloalkyl" refers to a non-aromatic carbon-based ring composed of at least three carbon atoms. Examples of cycloalkyl groups include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and the like. The term "heterocycloalkyl group" is a cycloalkyl group as defined above where at least one of the carbon atoms of the ring is substituted with a heteroatom such as, but not limited to, nitrogen, oxygen, sulfur, or phosphorous.

"Heterocycloalkyl" and "heterocyclic" are used interchangeably herein.

The term "halogen" refers to fluoro, bromo, chloro and iodo substituents. The terms 'halogenated alkyl" or "haloalkyl group" refer to an alkyl group as defined above with one or more hydrogen atoms present on these groups substituted with a halogen (F, CI, Br, I).

The term "hydroxyl" is represented by the formula -OH.

"Nitro" refers to an R-group having the structure -N0₂.

Disclosed herein are boron-nitrogen polycyclic compounds that can function as organic scintillators. Scintillators exhibit luminescent emission when excited by certain radiation. The boron-nitrogen polycyclic compounds disclosed herein can (i) serve as potential thermal neutron detectors via the ¹⁰B thermal neutron capture reaction due to the presence of boron in the compounds, (ii) detect fast-neutrons by scattering of neutrons with the hydrogen atoms of the compound, and (iii) produce a detectable response upon capture of the fast neutrons and the slow neutrons. In certain embodiments, the compounds can be used for neutron detection that can discriminate between γ-ray and neutron events. In further embodiments, the compounds can be used for detecting ionizing radiation such He²⁺, Li⁺, and γ-rays.

In certain embodiments, the boron-nitrogen polycyclic compounds are 1,2-azaborine acenes. Illustrative 1,2-azaborine acenes include 1,2-azaborine analogs (which may have more than one boron-nitrogen conjugate motif) of, for example, anthracene, tetracene, pentacene, phenanthrene, benzoanthracene, benzophenanthrene, or benzopyrene.

In certain embodiments, the boron-nitrogen polycyclic compounds have a structure of:

Formula 1 wherein A is at least one fused, optionally substituted, aromatic ring; and R 1 and R 2 are each individually selected from H, optionally substituted alkyl (particularly lower alkyl), optionally substituted aryl, optionally substituted alkoxy, acyl, acyloxy, alkoxycarbonyl, amino,

aminocarbonyl, aryloxy, carboxyl, optionally substituted cycloalkyl, halogen, or hydroxyl; or

Formula 2 wherein each of R³ and R⁴ are each individually selected from H, optionally substituted alkyl (particularly lower alkyl), optionally substituted aryl, optionally substituted alkoxy, acyl, acyloxy, alkoxycarbonyl, amino, aminocarbonyl, aryloxy, carboxyl, optionally substituted cycloalkyl, halogen, or hydroxyl, provided that at least one of R³ or R⁴ is a fused polycyclic aromatic moiety.

In certain embodiments, A of Formula 1 has a structure of:

Formula 3 wherein ring B is fused to the boron-nitrogen ring of Formula 1, rings B and C are each aromatic rings; X¹, X², X³ and X⁴ are each C, or X¹ is B, X² is N, and X³ and X⁴ are each C, or X³ is B, X⁴ is N, and X¹ and X² are each C; and R⁵, R⁶, R⁷, R⁸, R⁹ and R¹⁰ are each individually selected from H, optionally substituted alkyl (particularly lower alkyl), optionally substituted aryl, optionally substituted alkoxy, acyl, acyloxy, alkoxycarbonyl, amino, aminocarbonyl, aryloxy, carboxyl, optionally substituted cycloalkyl, halogen, or hydroxyl.

In other embodiments, ring A of Formula 1 is a single fused optionally substituted benzene ring. R 1 and R 2 of Formula 1 are particularly H, aryl (e.g., phenyl) or lower alkyl. In certain embodiments of Formula 2, R⁴ is an anthryl-containing group, particularly a para-substituted anthryl group wherein the para-substituent is phenyl, or a 1,2-azaborine ring; and R is H. In certain embodiments of Formula 3, R⁵ and R⁶ are each phenyl. In certain embodiments of Formula 3, X³ is B and X⁴ is N. In certain embodiments of Formula 3, X¹ is B and X² is N.

Illustrative compounds of formula 1 include:

is excluded from the compounds of formula 1 or 3. Illustrative compounds of formula 2 include:

However, in certain embodiments a compound having a structure of:

is excluded from the compounds of formula 2.

In further embodiments, the boron-nitrogen polycyclic compounds have a structure of:

Formula IA

In certain embodiments of Formula IA, R²⁰ is not H; X³ is B; X⁴ is N; R⁸, R⁹ and R¹⁰ are each H; X 1¹ and X2" are each C; and R 7 is not H. In certain embodiments, R 7 and R 20 have the same structure. In certain embodiments, R 7 and R 20 are each aryl or alkyl. R 1 and R 2 of Formula 1 A are particularly H, aryl (e.g., phenyl) or lower alkyl.

The compounds disclosed herein may exhibit favorable properties for performance as organic scintillators including a high overall light yield (YL) (for example, 20,000 Ph/MeV), a high α/β ratio (for example, at least 0.1), and a large discrimination figure of merit (FOM) (for example, at least 3).

The compounds disclosed herein may be included as a component of a neutron detection device. A neutron detection device includes a single crystal of the boron-nitrogen compound of at least 1 cm . The single crystal is coupled to a photomultiplier tube (PMT) which is in turn coupled to electronics which amplify the signal and discriminate between neutron and gamma scintillation events. The boron-nitrogen compound is in a solid state as a single crystal with no solvents or other additives. The compounds disclosed herein may be synthesized as shown in FIGS. 3-5. BN anthracene may be synthesized from 3-vinyl-2-aminonaphthalene (FIG. 3, eq (1)) and boron trichloride and subsequent substitution of the B-chlor bond with LiAlH₄. The mirror- symmetric BN2s anthracene may be prepared from 4,6-divinylbenzene-l,3-diamine and boron trichloride (FIG. 3, eq (2)). The corresponding C2-symmetric BN2c anthracene isomer may be synthesized from 2,5-divinylbenzene-l,4-diamine and boron trichloride (FIG. 3, eq (3)). BNli

diphenylanthracene may be assembled using l,4-diphenyl-3-vinyl-2-aminonaphthalene and boron trichloride using the same reaction mechanism (FIG. 3, eq (4)).

A different synthetic approach may be taken for BN1 diphenylanthracene and BN2 diphenylanthracene. A versatile nucleophilic substitution protocol for the incorporation of the 1,2- azaborine motif into various structures via intermediate A may be used (FIG. 3, eq (5)). For instance, BN1 diphenylanthracene may be prepared using A and 9,10-dibromoanthracene (after a cross-coupling reaction with phenylboronic acid and metal-halogen exchange) via the nucleophilic substitution approach (FIG. 3, eq (5)). This general approach may be adapted to the synthesis of BN2 diphenylanthracene (FIG. 3, eq (6)).

FIG. 4 depicts the general synthesis that includes synthesizing the vinyl amino intermediate, which is then reacted with boron trichloride to produce a ring-closed N-B-Cl intermediate, which then undergoes nucleophilic substitution of the CI atom.

Example 1

FIG. 5 shows the synthesis for making BN phenanthrene.

2-aminonaphthalene (1): Benzylidene-2-naphthylamine (13.5 g, 58 mmol) was dissolved in H₂0/Methanol (500 mL, 10: 1) and concentrated HCl (49 mL, 0.538 mol) was added drop wise to the stirring solution. After stirring for 2 hours, reaction mixture was washed 3x with Et₂0, and the aqueous layer was basified with 5M NaOH. The basified layer was then extracted 3x with Et₂0, the extract was dried over MgS0₄, and then concentrated in vacuo to yield a fluffy pink solid. (6.5 g, 78%) 1H NMR (300 MHz, cd₂cl₂) δ 7.72 (t, J = 9.2 Hz, 1H), 7.63 (d, J = 8.2 Hz, 1H), 7.40 (t, J = 7.5 Hz, 1H), 7.26 (t, J = 1.4 Hz, 1H), 7.02 (s, 1H), 7.04 - 6.97 (m, 1H), 3.96 (s, 1H). l-Iodo-2-naphthylamine (2): 2-aminonaphthalene (3.0 g, 20.95 mmol) was dissolved in 180 mL MeOH and NaI0₃ and NaS0₃ were dissolved in 135 mL of H₂0. After combining these two solutions, concentrated HC1 was added drop wise until the solution turned a deep purple color. After letting stir at rt for 2 hours, the solution was extracted 3x with Et₂0 and the extracted Et₂0 was washed lx with NaS₂0₃, 3x with brine, dried with MgS0₄ and concentrated in vacuo. The crude product was purified via flash chromatography eluting with 1: 1 Hexane:DCM (4.89 g, 87%) 1H NMR (500 MHz, cd₂cl₂) δ 7.97 (d, J = 8.5 Hz, 1H), 7.69 (dd, J = 13.6, 8.4 Hz, 2H), 7.52 (dt, 1H), 7.32 (t, J = 7.5 Hz, 1H), 7.06 (d, J = 8.7 Hz, 1H), 4.57 (s, 2H). ¹³C NMR (126 MHz, c₆d₆) δ 147.71, 137.34, 131.57, 131.51, 130.19, 129.99, 129.84, 124.66, 118.72, 84.19. l-vinyl-2-naphthylamine (3): In a glove box, an oven dried 2 necked round bottom flask was charged with Pd(dppf)Cl₂-CH₂Cl₂ (330 mg, 0.405 mmol) and potassium vinyltrifluoroborate (1.62 g, 12.13 mmol) and fitted with a condenser. A separate flask was charged with l-iodo-2- naphthylamine (2.18g, 8.09 mmol), triethylamine (1.25 mL, 8.89 mmol), n-PrOH (60 mL) and purged with N₂ for 20 min. After purging, this solution was transferred via cannula into the reflux condenser and let reflux overnight under N₂. In the morning, the reaction was let cool to rt and 60 mL of cold H₂0 was added. The resulting mixture was extracted 3x with Et₂0, washed with brine, concentrated and purified via flash chromatography eluting with DCM. (1.03 g 75.5%) 1H NMR (300 MHz, cd₂cl₂) δ 7.88 (d, J = 8.5 Hz, 1H), 7.72 (d, J = 8.0 Hz, 1H), 7.63 (d, J = 8.8 Hz, 1H), 7.43 (t, J = 7.6 Hz, 1H), 7.27 (t, J = 7.4 Hz, 1H), 7.08 - 6.93 (m, 2H), 5.85 (dd, J = 11.4, 1.9 Hz, 1H), 5.65 (dd, J = 18.0, 1.9 Hz, 1H), 4.20 (s, 2H). ¹³C NMR (126 MHz, cede) δ 143.15, 134.63, 134.21, 130.26, 129.93, 129.69, 128.17, 124.92, 123.88, 122.49, 120.11, 117.25.

N-H B-H Phenanthrene (5): In a glove box a 300 mL pressure vessel was charged with l-vinyl-2- naphthylamine (879 mg, 5.14 mmol) 100 mL of toluene and cooled to -20 °C. Cold BC1₃ (1 M in Hex, 7.71 mL, 7.71 mmol) was added to the vigorously stirring cold solution of amine in toluene and this was then let warm to rt and then heated at 100 °C overnight. In the morning, the toluene was removed under reduced pressure. In a glove box, the remaining residue was re-dissolved in Et₂0 and cooled to -20 °C. In a separate flask, LAH (390 mg, 10.28 mmol) was dissolved in Et₂0 and cooled to -20 °C. The two cold fractions were combined in the glove box, and let warm to rt with stirring overnight. In the morning, HCl (2 M in Et ₂0, 5.4 mL, 10.79 mmol) was added and the resulting mixture was filtered through a silica gel plug. The product was purified via flash chromatography eluting with pentane. (682 mg, 74% over 2 steps) ^UB NMR (96 MHz, cd₂cl₂) δ 31.12 (d, J = 110.3 Hz). 1H NMR (600 MHz, cd₂cl₂) δ 9.08 (d, J = 11.6 Hz, 1H), 8.61 (s, 1H), 8.58 (d, J = 8.5 Hz, 1H), 7.91 (d, J = 8.0 Hz, 1H), 7.88 (d, J = 8.8 Hz, 1H), 7.66 (t, J = 1.3 Hz, 1H), 7.52 (t, J = 7.4 Hz, lH), 7.44 (d, J = 8.8 Hz, 1H), 7.23 (d, J = 11.6 Hz, 1H), 5.54 - 4.56 (m, 2H). ¹³C NMR (151 MHz, cd₂cl₂) δ 139.24, 138.37, 131.08, 130.14, 129.42, 129.32, 128.63, 127.02, 127.00, 124.49, 124.47, 121.61, 121.59, 119.83, 119.14.

Example 2

FIG. 6 shows a proposed synthesis for BN anthracene

Methyl 3-amino-2-naphthoate (10): 3-amino-2-naphthoic acid (1.78 g, 9.5 mmol) was dissolved in acidic methanol (80 mL MeOH, 12.4 mL H₂S0₄) and refluxed overnight. The mixture was cooled, concentrated and neutralized with a saturated solution of Na₂C0₃. The resulting precipitate was filtered off, washed with water and dissolved with DCM. The filtrate was extracted 2x with DCM and the combined DCM fractions were washed with water, dried over MgS0₄, and concentrated in vacuo. (1.6 g, 85.4%)

(3-aminonaphthalen-2-yl)methanol (11): A solution of 10 (1.6 g, 8.12 mmol) in dry THF was cooled to 0 °C under N₂ and a solution of LAH (493 mg, 13 mmol) in dry THF was added drop wise. The reaction was stirred at 0 °C for 2 hours and then quenched with water. The precipitate was filtered and washed 3x with THF. The filtrated was collected and concentrated in vacuo. (1.4 g,

99%)

N-(3-(hydroxymethyl)naphthalen-2-yl)pivalamide (12): To an ice cold solution of 11 (1.4 g, 8.12 mmol) and TEA (1.7 mL, 12.3 mmol) in DCM was slowly added a solution of pivaloyl chloride (1.26 mL, 10.23 mmol) in DCM. The reaction mixture was allowed to slowly warm to room temperature with stirring overnight. In the morning, the reaction mixture was concentrated in vacuo and the crude product was digested with a 3% HCl solution for 1 hour. The product was collected via filtration (1.9 g, 91%) N-(3-formylnaphthalen-2-yl)pivalamide (13): To a solution of 12 (1.9 g, 7.4 mmol) in DCM was added activated Mn0₂ (3.2 g, 37 mmol) The reaction mixture was stirred at rt and monitored via TLC eluting with EtOAc: Hexanes (1:3). After 1 hour, a second portion of Mn0₂ was added and a third portion was added after 3 hours. After reacting overnight, the reaction mixture was filtered through a celite plug and purified via flash chromatography eluting with DCM. (773 mg, 40%)

N-(3-vinylnaphthalene-2-yl)pivalamide(14): In a glove box an oven dried round bottom flask was charged with THF (40 mL) and methyltriphenylphosphonium bromide (1.2 g, 3.4 mmol). To this flask was added nBuLi (1.36 mL, 2.5M in hexane, 3.4 mmol), and this mixture was let stir at rt for 2 hours. A solution of 13 in THF was added dropwise and let react at rt for 4 hours. The reaction was quenched with a saturated solution of ammonium chloride, extracted 3x with DCM, dried and concentrated in vacuo to yield a crude yellow oil that was purified via flash

chromatography eluting with DCM. (376.1 mg, 52,4%)

3-vinyl-2-naphthylamine (15): A round bottom flask was charged with 14, 2N HC1 (55 mL) and EtOH (37 mL) This solution was refluxed overnight. In the morning, the reation mixture was cooled and filtered and the filtrate was neutralized with saturated NaC0₃. The precipitate was filtered, dissolved in DCM, dried over MgS0₄ and concentrated in vacuo to yield the desired product.

The reaction conditions established for the synthesis of the naphthalene and phenanthrene should yield the BN anthracene when starting from 3-vinyl-2-naphthlyamine (15).

Example 3

For the testing of the organic scintillator, single crystal emission under x-ray irradiation, light yield using several gamma ray and neutron sources (22Na, 137Cs 252Cf, and Am/Be) and pulse shape discrimination (PSD) using both the Am/Be and 252Cf source were measured. The results shown in FIGS. 7A-7E indicate that N-H B-phenyl naphthalene scintillates under gamma and neutron radiation, The figures show fluorescence under x-ray excitation, light output under a gamma source (22Na) and under a neutron/gamma source (Am/Be and 252Cf). Additionally in the figure where the compound was irradiated with a neuton/gamma source (Am/Be) it is shown that there is a peak in the spectrum that disappears when the scintillator is shielded against thermal neutrons indicating that this sample is able detect thermal neutrons.

FIG. 12 and 13 show that BN anthracenes have similar emission profiles as the

carbonaceous anthracene, thus likely have similarly good scintillation properties (but with the added benefit of the inclusion of the element boron for thermal neutron detection).

Example 4

This synthesis is shown in FIG. 8.

3-iodo-2-naphthoic acid (17): To an ice cold solution of 3-amino-2-naphthoic acid (10 g, 53.4 mmol) (16) in water (100 mL), crushed ice (50 g), and concentrated HCl (907.8 mmol, 76 mL) was added NaN0₂ (4.42 g, 64.1 mmol) in 20 mL water. This solution was let stir at 0 °C for 30 minutes. KI (17.73 g, 106.8 mmol) in 40 mL water was added dropwise at 0 °C. This was let stir at 0°C for 5 minutes, then heated to 90 °C for one hour. The reaction mixture was then cooled to room temperature and extracted 4 times with EtOAc. The extract was washed 3x with saturated NaHS0₃, 3x with brine, dried over MgS0₄, and concentrated. (14.8 g, 87.7%) ¹H NMR (300 MHz, DMSO- <k) δ 13.30 (s, 1H), 8.64 (s, 1H), 8.39 (s, 1H), 8.05 (d, J = 7.7 Hz, 1H), 7.94 (d, J = 1.6 Hz, 1H), 7.70 - 7.53 (m, 3H).

3-iodonaphthalen-2-amine (18): Diphenyl phosphoryl azide (15.2 mL, 70.45 mmol), 3-iodo-2- naphthoic acid (14.0 g, 46.97 mmol), and triethylamine (9.83 mL, 70.45 mmol) were combined in DMF (375 ml), and let stir under N₂. After 3 hours of stirring, water (47 mL) was added and the solution was heated to 90 °C for 1 hour. The reaction mixture was let cool to room temperature and diluted with 500 mL of water. A pseudo counter current extraction was performed where the reaction mixture was washed 5x with Et₂0 and each Et₂0 extraction was washed 5x with water. The Et₂0 layers were combined, washed 2x with a saturated solution of NaHC0₃, 2x brine, dried over MgS0₄, and concentrated. (11.18 g, 88.5%) 1H NMR (300 MHz, Methylene Chloride- ₂) δ 8.29 (s, 1H), 7.62 (t, J = 8.5 Hz, 2H), 7.41 (ddd, J = 8.2, 6.8, 1.4 Hz, 1H), 7.25 (ddd, J = 8.2, 6.8, 1.3 Hz, 1H), 7.13 (s, 1H), 4.32 (s, 2H).

3-vinyl-naphthylene-2-amine (19): In a glove box, an oven dried 3 necked round bottom flask was charged with Pd(dppf)Cl₂-CH₂Cl₂ (1.7 g, 2.08 mmol), potassium vinyltrifluoroborate (6.68 g, 49.9 mmol), 3-iodonaphthalen-2-amine (11.18 g, 41.6 mmol), triethylamine (7.0 mL, 49.9 mmol), and toluene (300 mL) A condenser was fitted to the flask and the flask was brought outside of the glovebox. n-PrOH (300 mL) which had been purged with N₂ for 2 hours was transferred via cannula to the reaction flask and this mixture was let reflux overnight under N₂. In the morning, the reaction was let cool to room temperature and 600 mL of cold H₂0 was added. The resulting mixture was extracted 3x with Et₂0, washed 3x with brine, concentrated and purified via a silica gel plug eluting with DCM. (4.55 g, 64.8%) 1H NMR (300 MHz, Methylene Chloride- ₂) δ 7.80 (s, 1H), 7.73 (d, J = 8.1 Hz, 1H), 7.60 (d, J = 8.2 Hz, 1H), 7.44 - 7.31 (m, 1H), 7.25 (dd, J = 8.2, 6.7 Hz, 1H), 7.03 (s, 1H), 6.96 (dd, J = 17.3, 10.9 Hz, 1H), 5.85 (dd, J = 17.4, 1.5 Hz, 1H), 5.48 (dd, J = 11.0, 1.5 Hz, 1H), 4.01 (s, 2H).

1,2-BN-anthracene (20): In a glove box a 1 L oven dried round bottomed flask was charged with 3-vinyl-naphthylene-2-amine (4.05 g, 23.9 mmol) 500 mL of toluene, fitted with a condenser, and cooled to -20 °C. Cold BC1₃ (1 M in Hex, 47.9 mL, 49.9 mmol) was added to the vigorously stirring cold solution of amine in toluene and this was then let warm to room temperature and then heated at reflux overnight. In the morning, the toluene was removed under reduced pressure. In a glove box, the unpurified product (-5.1 g, 23.9 mmol) was re-dissolved in Et₂0 and cooled to -20 °C. In a separate flask, LAH (1.82 g, 47.9 mmol) was dissolved in Et₂0 and cooled to -20 °C. The two cold fractions were combined in the glove box, and let warm to rt with stirring overnight. In the morning, HC1 (2 M in Et ₂0, 26.29 mL, 52.58 mmol) was added and the resulting mixture was filtered through a silica gel plug. The product was purified via recrystallization from hot chlorobenzene (3.4 g, 79.6% over 2 steps) ⁿB NMR (96 MHz, Methylene Chloride- ₂) δ 32.29 (d, J = 133.1 Hz). 1H NMR (600 MHz, Methylene Chloride- ₂) δ 8.36 (s, 1H), 8.25 (d, J = 11.5 Hz, 1H), 8.23 (s, 1H), 8.00 (d, J = 8.3 Hz, 1H), 7.92 (d, J = 8.4 Hz, 1H), 7.77 (s, 1H), 7.54 (ddd, J = 8.2, 6.7, 1.2 Hz, 1H), 7.45 (ddd, J = 8.0, 6.7, 1.2 Hz, 1H), 7.02 (dt, J = 11.5, 2.0 Hz, 1H), 5.48 - 4.73 (m, 2H). Example 5

This synthesis is shown in FIG. 9.

2,5-dibromoterephthalic acid (22): To a 500 mL round bottom flask was added l,4-dibromo-2,5- dimethyl benzene (21) ( 18.0 g, 68.7 mmol), a 1: 1 solution of t-BuOH and water (250 mL) and KMn0₄ (24 g, 151.2 mmol). After refluxing this mixture for 1 hour, an addition portion of KMn0₄ was added (24 g, 151.2 mmol) and the reaction was let reflux overnight. After allowing to cool to room temperature, the reaction mixture was filtered through celite and the t-BuOH was removed under reduced pressure. The reaction mixture was then acidified with concentrated HC1 and the resulting precipitate was collected and recrystallized from hot EtOH. (18.4 g, 82.7%) 1H NMR (300 MHz, DMSO- ) δ 7.98 (s, 1H), 4.95 (s, 11H).

Tert-butyl 2,5-dibromo-l,4-phenylene dicarbamate (23): Diphenyl phosphoryl azide (9.8 mL, 45.4 mmol), 2,5-dibromoterephthalic acid (4.9 g, 15.14 mmol), and triethylamine (6.33 mL, 45.4 mmol) were combined in t-BuOH (175 ml), and let reflux for 12 hours under N₂. The reaction mixture was let cool to room temperature and diluted with 175 mL of water. The reaction mixture was then extracted 3x with Et₂0 The Et₂0 layers were combined and then washed 3x brine, dried over MgS0₄, and concentrated. The crude reaction mixture was purified via flash chromatography eluting with DCM (4.16 g, 60.0%) 1H NMR (300 MHz, Chloroform- ) δ 8.41 (s, 1H), 6.91 (s, 1H), 1.56 (s, 9H).

Tert-butyl 2,5-divinyl-l,4-phetylene dicarbamate (24): In a glove box, an oven dried 3 necked round bottom flask was charged with Pd(dppf)Cl₂-CH₂Cl₂ (.713 g, .873 mmol), potassium vinyltrifluoroborate (3.51 g, 26.19 mmol), tert-butyl 2,5-dibromo-l,4-phenylene dicarbamate (4.068 g, 8.73 mmol), triethylamine (2.9 mL, 20.95 mmol), and toluene (200 mL) A condenser was fitted to the flask and the flask was brought outside of the glovebox. n-PrOH (200 mL) which had been purged with N₂ for 2 hours was transferred via cannula to the reaction flask and this mixture was let reflux overnight under N₂. The reaction was let cool to rt and 600 mL of cold H₂0 was added. The resulting mixture was extracted 3x with Et₂0, washed with brine, concentrated and purified via a silica gel plug eluting with DCM. (2.6 g, 82.8%) 1H NMR (300 MHz, Chloroform- ) δ 7.86 (s, 1H), 6.80 (dd, J = 17.5, 11.2 Hz, 1H), 6.37 (s, 1H), 5.76 (d, J = 18.2 Hz, 1H), 5.44 (d, J = 10.9 Hz, 1H), 1.64 - 1.49 (m, 9H).

2,5-divinylbenzene-l,4-diamine (25): Tert-butyl 2,5-divinyl-l,4-phetylene dicarbamate (2.60 g, 7.23 mmol) was dissolved in DCM (27 mL) and trifluoroacetic acid (13.5 mL) was added with stirring. The solution was let stir at room temperature for 2 hours and then the solvent was removed under reduced pressure. The resulting material was redissolved in EtOAc, washed 3x with NaHC0₃, 3x with brine, dried over MgS0₄ and concentrated. The crude material was purified via flash chromatography eluting with DCM:EtOAc (4: 1) (837.7 mg, 72.3%) 1H NMR (500 MHz, Chloroform- ) δ 7.29 (s, 1H), 6.78 (dd, / = 17.5, 11.1 Hz, 5H), 6.74 (s, 4H), 5.66 - 5.59 (m, 4H), 5.31 (dd, / = 11.0, 1.5 Hz, 4H), 3.47 (s, 11H). ¹³C NMR (126 MHz, cdcl₃) δ 136.39, 132.35, 125.60, 115.39, 115.06.

Anti-BN-Anthracene (26): In a glove box a 250 mL oven dried round bottomed flask was charged with 2,5-divinylbenzene-l,4-diamine (491.6 mg, 3.07 mmol) 100 mL of toluene, fitted with a condenser, and cooled to -20 °C. Cold BC1₃ (1 M in Hex, 12.3 mL, 12.3 mmol) was added to the vigorously stirring cold solution of the diamine in toluene and this was then let warm to room temperature and then heated at reflux overnight. In the morning, the toluene was removed under reduced pressure. In a glove box, the unpurified product (-763.5 mg, 3.07 mmol) was re-dissolved in Et₂0 and cooled to -20 °C. In a separate flask, LAH (466.0 mg, 12.28 mmol) was dissolved in Et₂0 and cooled to -20 °C. The two cold fractions were combined in the glove box, and let warm to rt with stirring overnight. In the morning, HC1 (2 M in Et₂0, 6.75 mL, 13.5 mmol) was added and the resulting mixture was filtered through a silica gel plug. The product was purified via recrystallization from hot chlorobenzene. (430.7 mg, 78%) ^UB NMR (96 MHz, Methylene Chloride- ₂) δ 34.53 - 28.72 (m). 1H NMR (300 MHz, Methylene Chloride- ₂) δ 8.38 (s, 1H), 8.18 (d, / = 11.4 Hz, 1H), 7.64 (s, 1H), 7.12 - 7.03 (m, 1H), 5.75 - 4.44 (m, 1H). Example 6

This synthesis is shown in FIG. 10.

1.5- dibromo-2,4-dimethyl benzene (28): To an ice cold solution of I₂(200 mg, .790 mmol) in m- xylene (19.75 ml, 160 mmol), Br₂ (17.4 mL, 340 mmol) was added dropwise in the dark. This solution was let stir at room temperature in the dark. After 16 hours, 100 mL of a 20% (w/v) KOH solution was added to the reaction mixture and stirred vigorously with mild heating until the orange color disappeared. Solids were filtered off and recrystallized from EtOH. (23.1 g, 54.6%) 1H NMR (300 MHz, Chloroform- ) δ 7.70 (s, 1H), 7.11 (s, 1H).

4.6- dibromoisophthalic acid (29): To a 500 mL round bottom flask was added l,5-dibromo-2,4- dimethyl benzene (28) (23.1 g, 87.5 mmol), a 1: 1 solution of t-BuOH and water (320 mL), and KMn0₄ ( 30.4 g, 192.5 mmol). After refluxing this mixture for 1 hour, an addition portion of KMn0₄ was added (30.4 g, 192.5 mmol) and the reaction was let reflux overnight. After allowing to cool to room temperature, the reaction mixture was filtered through celite and the t-BuOH was removed under reduced pressure. The reaction mixture was then acidified with concentrated HC1 and the resulting precipitate was collected and recrystallized from hot EtOH. (22.5 g, 96.4%) 1H NMR (300 MHz, DMSO- ₆) δ 13.78 (s, 1H), 8.16 (s, OH), 8.14 (s, 1H).

Tert-butyl 4,6-dibromo-l,3-phenylenedicarbamate (30): Diphenyl phosphoryl azide (9.8 mL, 45.4 mmol), 4.6-dibromoisophthalic acid (29) (4.9 g, 15.14 mmol), and triethylamine (6.33 mL, 45.4 mmol) were combined in t-BuOH (175 ml), and let reflux for 12 hours under N₂. The reaction mixture was let cool to room temperature and diluted with 175 mL of water. The reaction mixture was then extracted 3x with Et₂0 The Et₂0 layers were combined and then washed 3x brine, dried over MgS0₄, and concentrated. The crude reaction mixture was purified via flash chromatography eluting with DCM (2.26 g, 32.1%) 1H NMR (300 MHz, Chloroform- ) δ 8.41 (s, 1H), 6.91 (s, 1H), 1.56 (s, 9H).

Tert-butyl 4,6-distyryl-l,3-phenylene dicarbamate (31): In a glove box, an oven dried 3 necked round bottom flask was charged with Pd(PPh₃)₄ (.24.8 mg, 0.0215 mmol), trans-vinylboronic acid (190 mg, 1.29 mmol), tert-butyl 4,6-dibromo-l,3-phenylene dicarbamate (200 mg, 0.43 mmol), NaC0₃ (273.4 mg, 2.56 mmol), toluene (6 mL), and Ethanol (4 ml) A condenser was fitted to the flask and the flask was brought outside of the glovebox. Water (2 mL) which had been purged with N₂ for 1 hour was transferred to the reaction flask and this mixture was let reflux overnight under N₂. The reaction was let cool to rt and 10 mL of cold H₂0 was added. The resulting mixture was extracted 3x with Et₂0, washed with brine, concentrated and purified via a silica gel plug eluting with DCM. (104.7 mg, 38.3%) 1H NMR (300 MHz, Methylene Chloride- ₂) δ 8.32 (s, 1H), 7.74 (s, 1H), 7.59 (d, J = 7.5 Hz, 4H), 7.47 - 7.37 (m, 4H), 7.37 - 7.30 (m, 2H), 7.14 (q, J = 16.2 Hz, 4H), 6.64 (s, 2H), 1.57 (d, J = 1.3 Hz, 22H).

4,6-distyrylbenzene-l,3-diamine (32): Tert-butyl 4,6-distyryl-l,3-phetylene dicarbamate (104.7 mg, 0.204 mmol) was dissolved in DCM (2 mL) and trifluoroacetic acid (0.5 mL) was added with stirring. The solution was let stir at room temperature for 2 hours and then the solvent was removed under reduced pressure. The resulting material was redissolved in EtOAc, washed 3x with

NaHC0₃, 3x with brine, dried over MgS0₄ and concentrated. The crude material was purified via flash chromatography eluting with DCM:EtOAc (4: 1) (55.4 mg, 86.8%) 1H NMR (300 MHz, Methylene Chloride- ₂) δ 7.57 (dd, J = 3.9, 2.1 Hz, 1H), 7.54 (s, 1H), 7.43 - 7.34 (m, 1H), 7.30 - 7.22 (m, 1H), 7.15 (d, J = 16.1 Hz, 1H), 6.98 (d, J = 16.1 Hz, 1H), 3.95 (s, 1H).

phenyl substituted syn-BN-anthracene (33): In a glove box a 20 mL oven dried round bottomed flask was charged with 4,-distyrylbenzene-l,3-diamine (55.4 mg, 0.177 mmol) 10 mL of toluene, fitted with a condenser, and cooled to -20 °C. Cold BC1₃ (1 M in Hex, 0.709 mL, 0.709 mmol) was added to the vigorously stirring cold solution of the diamine in toluene and this was then let warm to room temperature and then heated at reflux overnight. In the morning, the toluene was removed under reduced pressure. In a glove box, the unpurified product (-70.8 mg, 0.177 mmol) was re- dissolved in Et₂0 and cooled to -20 °C. In a separate flask, LAH (26.9 mg, 0.708 mmol) was dissolved in Et₂0 and cooled to -20 °C. The two cold fractions were combined in the glove box, and let warm to rt with stirring overnight. In the morning, HCl (2 M in Et_>20, 0.39 mL, 0.79 mmol) was added and the resulting mixture was filtered through a silica gel plug. The product was purified via recrystallization from hot chlorobenzene. (430.7 mg, 78%) ⁿB NMR (96 MHz, Methylene Chloride- d₂) δ 33.27 1H NMR (300 MHz, Methylene Chloride- d₂) δ 8.52 (s, 1H), 8.36 (s, 1H), 8.17 (s, 1H), 7.87 - 7.79 (m, 2H), 7.49 (t, J = 7.6 Hz, 2H), 7.37 (d, J = 7.7 Hz, 1H), 7.33 (s, 1H), 5.38 (m). In view of the many possible embodiments to which the principles of the disclosed invention may be applied, it should be recognized that the illustrated embodiments are only preferred examples of the invention and should not be taken as limiting the scope of the invention.

Claims

What is claimed is:

1. A method for detecting thermal and fast neutron emission comprising;

placing a boron-nitrogen polycyclic material in an environment for detecting possible thermal and fast neutron emission, wherein the detection can discriminate between neutron emission and gamma-ray emission.

2. A method for detecting the presence of a nuclear material, comprising:

3. The method of claim 1, wherein the neutron emission is from a nuclear material.

4. The method of any of claims 1 to 3, wherein the boron-nitrogen polycyclic material comprises a compound having a structure of:

Formula 1 wherein A is at least one fused, optionally substituted, aromatic ring; and R 1 and R 2 are each individually selected from H, optionally substituted alkyl, optionally substituted aryl, optionally substituted alkoxy, acyl, acyloxy, alkoxycarbonyl, amino, aminocarbonyl, aryloxy, carboxyl, optionally substituted cycloalkyl, halogen, or hydroxyl; or

Formula 2 wherein each of R³ and R⁴ are each individually selected from H, optionally substituted alkyl, optionally substituted aryl, optionally substituted alkoxy, acyl, acyloxy, alkoxycarbonyl, amino, aminocarbonyl, aryloxy, carboxyl, optionally substituted cycloalkyl, halogen, or hydroxyl, provided that at least one of R³ or R⁴ is a fused polycyclic aromatic moiety.

5. The method of claim 4, wherein A of Formula 1 has a structure of:

6. The method of claim 4 or 5, wherein R 1 and R 2 of Formula 1 are each individually H, aryl, or lower alkyl.

7. The method of claim 6, wherein R 1 is H and R 2 is aryl.

8. The method of claim 4, wherein R⁴ is an anthryl-containing group.

9. The method of any one of claims 5 to 7, wherein R⁵ and R⁶ are each phenyl.

10. The method of any one of claims 5 to 7, or 9, wherein R 7 , R 8 , R 9 and R 10 are each individually H.

11. The method of any one of claims 1 to 10, wherein the boron-nitrogen material is not:

12. The method of any one of claims 1 to 3, wherein the boron-nitrogen poly material is a 1,2-azaborine analog of anthracene, tetracene, pentacene, phenanthrene,

benzoanthracene, benzophenanthrene, or benzopyrene.

13. A compound having a structure of:

14. The compound of claim 13, wherein R 1 and R 2 of Formula 1 are each individually H, aryl, or lower alkyl.

15. The compound of claim 13 or 14, wherein R 1 is H and R 2 is aryl.

16. The compound of any one of claims 13 to 15, wherein R⁵ and R⁶ are each phenyl.

17. The compound of any one of claims 13 to 16, wherein R 7 , R 8 , R 9 and R 10 are each individually H.

18. A compound having a structure of:

19. The compound of claim 18, wherein R is an anthryl-containing group.

20. A device for detecting thermal and fast neutron emission comprising:

a crystal of a boron-nitrogen polycyclic material that can detect thermal and fast neutron emission, and discriminate between neutron emission and gamma-ray emission.

21. The compound of any one of claims 13 to 17, wherein X³ is B and X⁴ is N.

22. The compound of any one of claims 13 to 17, wherein X 1 is B and X 2 is N.

23. The compound of claim 1, wherein the compound is selected from:

A compound having a structure of:

Formula IA