Synthesis and oxidation of (benzimidazolylidene)Cr(CO)5 complexes

Synthesis, characterization, molecular structures, cytotoxic and antibacterial activities of N,N′-diaryl-o-phenylenediamines

“…It seems that these molecules take advantage of both a degree of tetrahedral distortion for amine N atoms and restricted rotation of phenyl rings, to minimize steric hindering. Such arrangement was previously observed in related 1,2,4,5-tetrakis(amino)benzene derivatives [21], as well as in organometallics bearing N-heterocyclic carbene derivatives [22,23] or diimine ligands [24]. The non-parallel arrangement typical of 2,6-diisopropylphenylamine derivatives is, for example, patent in X-ray structures reported for boryllithium salts [25].…”

“…2, inset). This arrangement, invariably found in secondary 1,2-diaminobenzene derivatives [21,22,26], avoids HÁ Á ÁH short contacts. In 1-3, amine HÁ Á ÁH separations are however close to the sum of van der Waals radii or even shorter: the shortest HÁ Á ÁH separation is 1.96 Å for 2 and the longest 2.34 Å for 1.…”

N-heterocyclic carbene complexes of Group 6 metals

“…This type of M(0) NHC complexes is classified according to the heterocyclic backbones in the carbene ligands, such as imidazole [73][74][75][76][77][78][79][80][81][82][83][84][85][86][87][88][89][90][91], benzimidazole [80,[92][93][94][95][96][97][98][99] and other heterocyclic compounds based-NHC ligands [94,[100][101][102][103][104][105][106][107][108]. M a n u s c r i p t…”

“…Apart from using free carbenes, synthesis of benzimidazole based NHC M(0) complexes through cyclisation reaction has been studied [97][98][99], as summarized in Figure functions in complexes Cr-13e and W-10g generated Cr-13g and W-10i [98]. In Cr-13e and W10g, both Cr-C carbene and W-C carbene distances are shorter than those found in Cr-13g and W-10i,…”

“…In 2005, Hirao et al reported the synthesis of (1,3-diaryl-2-benzimidazolylidene)Cr(CO) 5 (Cr-13(h,i)) by the addition of lithium 1,2-phenylenediamides to Cr(CO) 6 in the presence of 12-crown-4 to generate a carbamoyl chromate intermediate, followed by the treatment of chlorotrimethyl-silane which promote the intramolecular nucleophilic attack of lithium amide togive the products[99]. 11 M(0) carbonyl complexes bearing benzimidazol-2-ylidene[97][98][99].…”