The occurrence of through-bond orbital interactions in an alpha,omega donor-acceptor substituted bi(cyclohexylidene) and bi(cyclohexyl). X-Ray diffraction, UV-Vis absorption and photoelectron spectroscopy, ab initio SCF-MO and natural bond orbital analyses
Wd. Oosterbaan et al., The occurrence of through-bond orbital interactions in an alpha,omega donor-acceptor substituted bi(cyclohexylidene) and bi(cyclohexyl). X-Ray diffraction, UV-Vis absorption and photoelectron spectroscopy, ab initio SCF-MO and natural bond orbital analyses, J CHEM S P2, (7), 2001, pp. 1066-1074
Citations number
55
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 2
The ground state sigma-pi and pi-pi* interactions in 2-[4-(1-phenylpiperidi
n-4-ylidene)cyclohexylidene]malononitrile (1) and 2-[4-(1-phenylpiperidin-4
-yl)cyclohexylidene]malononitrile (2) have been studied. Both the ionizatio
n potentials of 1 and 2, and ab initio RHF/6-31G calculations in combinatio
n with a natural bond orbital analysis show that the ground state through-b
ond interaction (TBI) between the 1-phenylpiperidine electron donor and the
dicyanoethylene electron acceptor in 1 and 2 is distinct but small. The ol
efinic bond in 1 enhances the interaction between the 1-phenylpiperidine el
ectron donor and the dicyanoethylene electron acceptor as compared to 2. Th
e TBI between the N,N-dialkylanilino donor and the olefinic bond in 1 can b
e modulated by rotation of the phenyl group around the C-N bond. The solid
state structures of 1 and 2 have been determined by single crystal X-ray di
ffraction. In the crystal intermolecular electron-donor-acceptor complexes
are formed, which give rise to an intermolecular charge transfer absorption
in the solid state.