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While the dithiolene-based N-heterocyclic silane (4) reacts with two equivalents of BX3 (X = Br, I) to give zwitterionic Lewis adducts 5 and 8, respectively, the parallel reaction of 4 with BCl3 results in 10, a dithiolene-substituted N-heterocyclic silane, via the Si-S bond cleavage. Unlike 5, the labile 8 may be readily converted to 9 via BI3-mediated cleavage of the Si-N bond. The formation of 5 and 8 confirms that 4 uniquely possesses dual nucleophilic sites: (a) the terminal sulphur atom of the dithiolene moiety; and (b) the backbone carbon of the N-heterocyclic silane unit. [ABSTRACT FROM AUTHOR]

The redox chemistry of the first stable anionic dithiolene radical 1Ṗ was investigated by both reactivity and cyclic voltammetry studies. While one-electron reduction of 1Ṗ by Cp2Co or KC8 affords the corresponding dithiolate dimers 2 and 3, respectively, one-electron oxidation of 1Ṗ by Ph3C+BF4− (or O2) conveniently gives 4, the neutral dithiolene dimer. [ABSTRACT FROM AUTHOR]

Reaction of 2-bromo-1,3,2-diazaborole (1) with excess BBr3 induces 1,2-hydrogen migration, giving 1,3,2-diazaborole-derived carbene complexes of boron bromide (2). Compound 2 exists in a dynamic solution equilibrium with 1. The 1H NMR study shows that the equilibrium lies to the right side of the dissociation reaction of 2. Parallel reaction of 1 with excess BI3 gives the corresponding 1,3,2-diazaborole-derived carbene boron iodide complex (3). Notably, in contrast to 2, the dissociation reaction of 3 largely lies to the left side, favouring the formation of 3. The dynamic solution equilibrium behaviours of 2 and 3 are probed by both experimental and theoretical methods. [ABSTRACT FROM AUTHOR]

While the 1 : 1 reaction of C4-trichlorosilyl-functionalized N-heterocyclic carbene (NHC) (2) with [(η5-C5H4Li)2Fe]3[TMEDA]2 (3) gives C4-sila[1]ferrocenophane-substituted NHC (4), C4-ferrocenylsilyl-bridged bis-NHC (6) is synthesized by combining 3 with C4-chlorodimethylsilyl-functionalized NHC (5) in a 1 : 2 ratio, (compound 5 is prepared by reaction of the anionic N-heterocyclic dicarbene (NHDC) [:C{[N(2,6-Pri2C6H3)]2CHCLi}]n (1) with Me2SiCl2). In addition, ligand 4- and 6-based GeCl2 complexes (7 and 8) are also synthesized. Compounds 4–8 have been characterized by 1H, 13C, and 29Si NMR spectroscopy and single crystal X-ray diffraction. [ABSTRACT FROM AUTHOR]

Reaction of the anionic N-heterocyclic dicarbene (NHDC), [:C{[N(2,6-Pri2C6H3)]2CHCLi}]n (1), with SiCl4 gives the trichlorosilyl-substituted (at the C4 carbon) N-heterocyclic carbene complex (7). Abnormal carbene–SiCl4 complex (8) may be conveniently synthesized by combining 7 with HCl·NEt3. In addition, 7 may react with CH2Cl2 in warm hexane, giving the abnormal carbene-complexed SiCl3+ cation (9). The nature of the bonding in 9 was probed with complementary DFT computations. [ABSTRACT FROM AUTHOR]

Low temperature reaction of N-heterocyclic carbene : BEt3 with nBuLi (in THF) initially gives the C4-lithiated N-heterocyclic carbene : BEt3 complex (4), which isomerizes to the C2-lithiated abnormal N-heterocyclic carbene : BEt3 complex (2) in refluxing THF. While reaction of 2 with GaCl3 gives a 4-functionalized N-heterocyclic carbene : GaCl3 adduct (6), reaction of 4 with GaCl3 affords the first abnormal carbene-gallium chloride complexes (5). [ABSTRACT FROM AUTHOR]