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Tetra(amino)methanes: Implications of Their Structure and Reactivity Pattern for Hypothetical Carbon Nitride Frameworks
Author(s) -
Jockisch Alexander,
Schier Annette,
Schmidbaur Hubert
Publication year - 1997
Publication title -
chemische berichte
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 0009-2940
DOI - 10.1002/cber.19971301206
Subject(s) - chemistry , nucleophile , tetra , nitride , crystal structure , carbon fibers , crystallography , methane , computational chemistry , stereochemistry , organic chemistry , medicinal chemistry , catalysis , materials science , composite number , composite material , layer (electronics)
Because of their possible role as model compounds for the structural units of carbon nitride C 3 N 4 , the preparation, structural chemistry, and some representative reactions of tetra(amino)methanes have been (re)investigated. In the crystal, C(NMe 2 ) 4 ( 1 ) has a molecular geometry close to D 2a symmetry as proposed by theoretical calculations using state‐of‐the‐art density functional methods. The coordination of the central carbon atom is distorted tetrahedral and the configuration of the nitrogen atoms is strongly pyramidal, as opposed to almost planar in the tetra(amino)silanes. Tetra(pyrrolidinyl)methane has a similar core structure, with all heterocyclic substituents in an envelop conformation flexible in solution. Tetra(piperidinyl)methane is more rigid in solution, owing to a more congested structure, with much higher inversion barriers for the six‐membered rings. Hydrolysis of 1 leads to MezNH and hexamethylguanidinium hydroxide, and treatment of 1 with HAuCl 4 (aq) affords crystalline [C(NMe 2 ) 3 ] 4 AuCl 4 − the structure of which has also been determined. Compound 1 is a strong nucleophile and can be used as an aminating agent, converting e.g. halosilanes into dimethylaminosilanes, with the guanidinium cation as the leaving group. The experimental results are discussed in the light of recent predictions regarding bulk carbon nitrides.