Recent Achievements on Functionalization within closo‐Decahydrodecaborate [B₁₀H₁₀]²⁻ Clusters

Abstract

Closo‐decahydrodecaborate anion, [B10H10]2−, is one of the most notable clusters in the family of hydroborates, partly attributed to its unique electronic structure and its thermal and chemical stability. The major challenge in the development of [B10H10]2− chemistry resides in its functionalization via the activation of exo‐polyhedral B−H bonds to B−L bonds to generate attractive molecular construction modules or ‘archetypes’ of useful applications. To date, the closo‐[B10H10]2− cage has been functionalized with a wide range of functional groups ‐L such as halogens, amines, thiols, alkoxy, hydroxyl and multifunctional moieties to yield mono‐ or poly‐substituted borate derivatives. In this review, we present the recent trends in the chemistry of closo‐decaborate with focus on the substitution reactions of hydrogen atoms by various entities.

Effect of Nature of Substituents on Coordination Properties of Mono- and Disubstituted Derivatives of Boron Cluster Anions [BnHn]2– (n = 10, 12) and Carboranes with exo-Polyhedral B–X Bonds (X = N, O, S, Hal)

“…In this reaction (Scheme 2), the process of substitution of an exo-polyhedral hydrogen atom for the ligand molecule is observed, which accompanies the copper(I) complexation. Note that these reactions are of particular interest because the [2-B 10 H 9 L] 2derivatives with azaheterocyclic ligands L cannot be obtained in the course of the acid-catalyzed nucleophilic substitution [94,95]; under acidic conditions, organic ligands (Bipy, Phen, BPA) are protonated to form salts [ The data obtained indicate that copper(II) cannot coordinate the monocharged substituted derivatives whereas copper(I) is able to form complexes with the inner-sphere boron cluster. The possibility of the Bipy molecule to bend across the linker C-C bond allows it to be coordinated by copper(I) and simultaneously to be attached to the boron cage.…”

“…Preparation of complex [Cu(CH 3 CN) 2 [B 10 H 9 Bipy].The substituted derivative [2-B 10 H 9 Bipy]in the complex is coordinated by the metal atom via nitrogen atoms (Cu-N 2.028(2) Å) and apical BH group (Cu-B(H) 2.601(3), Cu-H(B)1.85(3)Å). In addition, two acetonitrile molecules are involved in copper(I) coordination (Cu-N 1.995(3),1.976(3) Å).Note that these reactions are of particular interest because the [2-B 10 H 9 L] 2derivatives with azaheterocyclic ligands L cannot be obtained in the course of the acid-catalyzed nucleophilic substitution[94,95]; under acidic conditions, organic ligands (Bipy, Phen, BPA) are protonated to form salts[LH] 2 [B 10 H 10 ] or [LH 2 ][B 10 H 10 ] [96,97].The data obtained indicate that copper(II) cannot coordinate the monocharged substituted derivatives whereas copper(I) is able to form complexes with the inner-sphere boron cluster. The possibility of the Bipy molecule to bend across the linker C-C bond allows it to be coordinated by copper(I) and simultaneously to be attached to the boron cage.…”

Ionic conduction in ammonia functionalised closo-dodecaborates MB12H11NH3 (M = Li and Na)

“…18 In contrast, the substitution of H atoms in Na 2 B 12 H 12 with halogens or OH groups was shown to shift the order-disorder phase transition to higher temperatures and consequently, cause low ionic conductivities at and near RT. 19,20 Beside these chemical modifications, polyhedral borohydride anions can also be functionalized with a variety of functional groups, such as amines, thiols, and oxo groups, 13,21 or by replacing a B-H unit in the cages with a heavy metal atom such as Pb 22 based on the activation and conversion of the B-H bond. 23 Because of such diversity in possible chemical modifications, to date only a small number of previously synthesised hydroborate-based compounds have been investigated as SSEs.…”

Synthesis of Disubstituted Carboxonium Derivatives of Closo-Decaborate Anion [2,6-B10H8O2CC6H5]−: Theoretical and Experimental Study

“…As an electrophile inducer, various Lewis and Bronsted acids (CF 3 COOH, CF 3 SO 3 H, BF 3 *Et 2 O, etc.) can be used [ 49 , 50 , 51 ]. Different organic molecules such as organic nitriles RCN, ethers R 2 O and thioethers R 2 S can be used as nucleophiles [ 52 , 53 ].…”