Modeling the configuration about the nitrogen atom in methyl- and silyl-substituted amines

Structure and crystal packing of 4-aminobenzonitriles and 4-amino-3,5-dimethylbenzonitriles at various temperatures

“…The N-phenyl bond length in M MD lies towards the value of 1.467 (2)A measured in 4-aminobenzonitrile hydrochloride crystals (Colapietro, Domenicano, Marciante & Portalone, 1981), which can be considered to be a pure single bond. It is of interest to note that this latter bond length is similar to that (1.453 A) found in the aliphatic trimethylamine (Blake, Ebsworth & Welch, 1984;Julian & Gibbs, 1988).…”

Bond length variation in hydronitride molecules and nitride crystals

“…Baur's (1987) report of a list of ionic radii for nitride crystals suggests, as observed for oxides, fluorides and sulfides, that molecular orbital (MO) calculations on hydronitride molecules should be capable of generating bond lengths and angles that reproduce those observed for nitride crystals. In fact, previous calculations on Si nitride (Julian and Gibbs 1985) and methyl-and silylsubstituted amine molecules (Julian and Gibbs 1988), show that the minimum energy bond lengths and angles not only match those observed for the molecules but also those observed for silicon nitride crystals. The present study (Buterakos 1990) was undertaken to learn whether the bond length -bond strength and bonded radii systematics observed for oxide and sulfide molecules and crystals also obtain for nitride molecules and crystals and whether the bonded radius of the nitride ion, rb(N), correlates with R(XN), as observed for the apparent radius of the nitride ion (O'Keeffe 1979).…”

Quantum-Chemical Study of the Structure and Properties of Hypothetical Superhard Materials Based on the Cubic Silicon−Carbon Nitrides

“…From this point of view, a rather interesting quantum-chemical investigation was undertaken earlier by Julian and Gibbs. 40 The authors have examined both the results of experimental studies and molecular orbital calculations (at the Hartree-Fock level of theory using 6-31G(d), 4-31G(d,p), and STO-3G(d) basis sets) for a series of methyland silyl-substituted amines, N(CH 3 ) 3-k …”

“…From this point of view, a rather interesting quantum-chemical investigation was undertaken earlier by Julian and Gibbs. 40 The authors have examined both the results of experimental studies and molecular orbital calculations (at the Hartree-Fock level of theory using 6-31G(d), 4-31G(d,p), and STO-3G(d) basis sets) for a series of methyland silyl-substituted amines, N(CH 3 ) 3-k (SiH 3 ) k (k ) 0, 1, 2, 3). It has been shown that transformation of the structure about the nitrogen atom from a planar configuration in trisilylamine (k ) 3) to a nearly tetrahedral one in trimethylamine (k ) 0) occurs.…”

“…Since the main structural characteristics (bond lengths and bond angles) of crystalline compounds like diamond and silicon solid are close to that for C(CH 3 ) 4 and Si(SiH 3 ) 4 molecules, respectively, it seems reasonable to assume that the similar small molecular systems could be used as models for the quantum-chemical studies of the structures of silicon−carbon nitrides. From this point of view, a rather interesting quantum-chemical investigation was undertaken earlier by Julian and Gibbs . The authors have examined both the results of experimental studies and molecular orbital calculations (at the Hartree−Fock level of theory using 6-31G(d), 4-31G(d,p), and STO-3G(d) basis sets) for a series of methyl- and silyl-substituted amines, N(CH 3 ) 3- k (SiH 3 ) k ( k = 0, 1, 2, 3).…”