Charge-transfer complexes. NH/sub 3/--F/sub 2/, NH/sub 3/--Cl/sub 2/, NH/sub 3/--ClF, N(CH/sub 3/)/sub 3/--F/sub 2/, N(CH/sub 3/)/sub 3/--Cl/sub 2/, and N(CH/sub 3/)/sub 3/--ClF

Journal Article · Tue Dec 09 23:00:00 EST 1975 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00858a001· OSTI ID:7296192

Lucchese, R R; Schaefer, III, H F

Nonempirical elecronic structure theory has been applied to several charge-transfer complexes, which involve ammonia and trimethylamine as electron donors, and molecular fluorine, chlorine, and ClF as electron acceptors. The self-consistent field calculations employed both minimum and double-zeta basis sets of contracted Gaussian functions. For NH/sub 3/-F/sub 2/ and NH/sub 3/-ClF, the importance of d functions on the N, F, and Cl atoms was investigated. In several cases the minimum basis results do not appear reliable. With the geometries of the donor and acceptor molecules fixed from experiment, the equilibrium geometries of the charge-transfer complexes were predicted. N-X (X = nearest halogen atom) distances are 3.08 A (NH/sub 3/-F/sub 2/), 2.93 A (NH/sub 3/-Cl/sub 2/), and 2.65 A (NH/sub 3/-ClF), while the predicted binding energies are 0.6 kcal (NH/sub 3/-F/sub 2/), 2.4 kcal (NH/sub 3/-Cl/sub 2/), and 7.7 kcal (NH/sub 3/-ClF). NH/sub 3/-FCl is predicted to be bound by less tha 0.1 kcal/mol. The most intriguing prediction is that the binding energies of the ammonia complexes are greater than those of the corresponding trimethylamine complexes. Although this prediction is in distinct disagreement with accepted chemical intuition, it is consistent with Mulliken populations, which suggest a significantly greater ''negative charge'' on the ammonia N atom than that for trimethylamine. Further, the dipole moment of NH/sub 3/ is significantly larger than that of N(CH/sub 3/)/sub 3/. (auth)

• Research Organization: Univ. of California, Berkeley
• OSTI ID: 7296192
• Journal Information: J. Am. Chem. Soc.; (United States), Journal Name: J. Am. Chem. Soc.; (United States) Vol. 97:25; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400301* -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
AMINES
AMMONIA
BINDING ENERGY
CHLORINE
CHLORINE COMPOUNDS
CHLORINE FLUORIDES
COMPLEXES
ELECTRON EXCHANGE
ELECTRON TRANSFER
ELEMENTS
ENERGY
EQUILIBRIUM
FLUORIDES
FLUORINE
FLUORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
HALOGENS
HYDRIDES
HYDROGEN COMPOUNDS
MOLECULAR STRUCTURE
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
NONMETALS
ORGANIC COMPOUNDS