Synthesis of 12-Substituted 1-Carba-closo-dodecaborate Anions and First Hyperpolarizability of the 12-C₇H₆⁺-CB₁₁H₁₁ Ylide [J. Am. Chem. Soc. 1999, 121, 3122−3126].

Abstract

The HRS ) 236 × 10 -30 esu first hyperpolarizability of the title ylide in CHCl 3 (1064 nm) obtained from hyper-Rayleigh scattering (HRS), using p-nitroaniline (pNA) The first molecular hyperpolarizability of the title ylide is within experimental error of that of pNA. With the new value for this standard, this is HRS ) 7.2 × 10 -30 esu, in much improved agreement with the INDO/S result calculated at zero frequency, zzz ) 1.7 × 10 -30 (the INDO/S result for pNA is zzz ) 18 × 10 -30 ). The structure of the dimeric porphyrin host 1 was inadvertently omitted.

Chemistry of the Carba-closo-dodecaborate(−) Anion, CB11H12-

“…Although perturbation of their spectra by the carborate anion may be of interest, only one such case seems to have received detailed attention due to possible utility in nonlinear optical applications. This is the zwitterion 12-C 7 H 6 + CB 11 H 11 -(51), 14 whose absorption spectrum is close to that of the tropylium cation C 7 H 7 + , shifted to longer wavelengths by the π-donor effect of the carborate anion. Both semiempirical 14 and ab initio 108 calculations have been done for this highly polar species with significant hyperpolarizability.…”

“…This is the zwitterion 12-C 7 H 6 + CB 11 H 11 -(51), 14 whose absorption spectrum is close to that of the tropylium cation C 7 H 7 + , shifted to longer wavelengths by the π-donor effect of the carborate anion. Both semiempirical 14 and ab initio 108 calculations have been done for this highly polar species with significant hyperpolarizability. 14 Little is known about the triplet energy of the parent 1, but an interesting observation has been made for its (7-12)-hexabromo derivative (178) and attributed to the "heavy-atom effect" of the bromine substituents on spinorbit coupling.…”

“…What is most needed at present is a high-yield one-step or two-step synthesis from cheap bulk chemicals. As we shall see in section 7, starting with bulk chemicals, at this time some 29 Ph H H I 162 36 Me Me Me OMe 196 13 TIPS H H I 163 36 Me Me Me OH 197 44 Me H Cl Cl 164 21 HS H H H 198 44 Me H Br Br 165 21 MeS H H H 199 14 Me H I I 166 21 Me2S + H H H 200 40 Me F F F 167 21 H H H M e 2S 201 45 Me Cl Cl Cl 168 21 H H H X g 202 41 Me Br Br Br 169 37 F H H H 203 41 Me Me 179 39 H H I I 213 15 Me Me Me F 180 40 H F F F 214 47 Me Me Me I 181 41 H C l C l C l 215 13 Me Me I Me 182 41 H B r B r B r 216 13 Me I Me Me 183 41 H I I I 217 13 Me Me I I 184 41 Br Br Br Br 218 48 F H Me Me 185 42 Me3N + H H I 219 48 Cl H Me Me 186 31 X d H H I 220 48 Cl Me Me Me 187 43 NH3 + H I I 221 48 Br Me Me Me 188 43 NH3 + I I I 222 48 I M e M e M e 189 14 H B r C l C l 223 49 H O H B r B r 190 14 H I Cl Cl 224 16 H H H X h 191 14 H C l B r B r 225 16 H H H X i 192 …”

Ethynylmonocarba-closo-dodecaborates: M[12-HCC-closo-1-CB11H11] and M[7,12-(HCC)2-closo-1-CB11H10] (M=Cs+, [Et4N]+)

“…In contrast to substitution reactions at the carbon vertex of the {closo-1-CB 11 } cluster that are well developed, the selective introduction of a functional group that can be modified easily at one of the boron vertices is less studied [1]. A strategy for the functionalization at the antipodal boron atom and the upper belt boron atoms of the {closo-1-CB 11 } cluster is the partial iodination followed by exchange of the iodine substituent(s) against an alkyl [20], aryl [20][21][22] allyl [23,24], or alkynyl [25] group(s) by Pd-catalyzed cross-coupling reactions, that was first introduced into boron cluster chemistry for the related neutral dicarba-closo-dodecaboranes in the early 1980s [26][27][28].…”

“…{closo-1-CB 11 } clusters with alkynyl substituents bonded to the boron atom in the antipodal position (B12) or to one of the boron atoms of the upper B 5 belt (B7) have been obtained. Mono-and diiodinated monocarba-closododecaborate anions that are accessible by iodination of the [closo-1-CB 11 H 12 ] À anion or of its derivatives [20,31,32] are the starting materials for these cross-coupling reactions with alkynyl Grignard reagents. In Scheme 1 the two-step syntheses of the anions SiCC-closo-1-CB 11 H 11 ] À and [7,12-(Me 3 SiCC) 2 -closo-1-CB 11 H 10 ] À starting from [closo-1-CB 11 H 12 ] À are depicted [25].…”