TY - JOUR
T1 - Tetra(amino)methanes
T2 - Implications of their structure and reactivity pattern for hypothetical carbon nitride frameworks
AU - Jockisch, Alexander
AU - Schier, Annette
AU - Schmidbaur, Hubert
PY - 1997
Y1 - 1997
N2 - Because of their possible role as model compounds for the structural units of carbon nitride C3N4, the preparation, structural chemistry, and some representative reactions of tetra(amino)methanes have been (re)investigated. In the crystal, C(NMe2)4 (1) has a molecular geometry close to D2d 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(pyrrolidinyljmethane 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 Me2NH and hexamethylguanidinium hydroxide, and treatment of 1 with HAuCl4(aq) affords crystalline [C(NMe2)3]+ AuCl4-, 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.
AB - Because of their possible role as model compounds for the structural units of carbon nitride C3N4, the preparation, structural chemistry, and some representative reactions of tetra(amino)methanes have been (re)investigated. In the crystal, C(NMe2)4 (1) has a molecular geometry close to D2d 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(pyrrolidinyljmethane 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 Me2NH and hexamethylguanidinium hydroxide, and treatment of 1 with HAuCl4(aq) affords crystalline [C(NMe2)3]+ AuCl4-, 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.
KW - Amination
KW - Carbon nitride
KW - Conformation analysis
KW - Guanidinium salts
KW - Tetra(amino)methanes
UR - http://www.scopus.com/inward/record.url?scp=0039783363&partnerID=8YFLogxK
U2 - 10.1002/cber.19971301206
DO - 10.1002/cber.19971301206
M3 - Article
AN - SCOPUS:0039783363
SN - 0009-2940
VL - 130
SP - 1739
EP - 1744
JO - Chemische Berichte
JF - Chemische Berichte
IS - 12
ER -