Rhenium aminocarbyne complex

Carvalho et al. reported molecular orbital calculations on the electron-rich rhenium isocyanide complex ReCl(CNH)(H2PCH2CH2PH2) and the aminocarbyne complex [ReCl(CNH2)(H2PCH2CH2PH2)] (37). They found that in the isocyanide complex a negative charge is accumulated on the Cl and N atoms. These two sites may therefore compete for electrophiles however, the product of N attack is thermodynamically favored. 

Addition of electrophiles to electron-rich isocyanide complexes is a proven synthetic method for the synthesis of aminocarbyne complexes (5,6). Reaction of the trimethylsilyl isocyanide rhenium complex 34 with HBF4 was reported by Pombeiro and co-workers (68). It leads to loss of the trimethylsilyl group and formation of the parent aminocarbyne ligand CNHj [Eq. (28)]. The CNHj ligand is easily interconverted to the CNH... 

The rhenium-carbon distance, 1.772(7) A, is, as expected, considerably shorter than those in the related vinylidene and q aminocarbyne complexes trans-[ReCl(=C=CHPh)(dppe)2] 2.046(8) A [5], and traT -[ReCl(=C-NHMe)(dppe)2][BF4], 1.80(3) 1 [8] (see below), respectively, in which there is a 7r-electron delocalisation along the... 

ISOCYANIDE -DERIVED AMINOCARBYNES 3.1. Rhenium Phosphinic Complexes... 

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