72558-73-7Relevant articles and documents
SOLID COMPLEXES OF THE Pi-AMPHOTERIC MOLECULE p-TRICYANOVINYL-N,N-DIMETHYLANILINE.
Sandman,Richter,Warner,Fekete
, p. 21 - 35 (1980)
Solid pi-complexes of p-tricyanovinyl-N,N-dimethylaniline (TCVDMA) were isolated for the first time. The complexing molecules include the simple aromatic solvents benzene, toluene, chlorobenzene, 1,2,4-trichlorobenzene, and N,N-dimethylaniline (DMA), 2,4,7-trinitrofluorenone (TNF), and p-chloranil. Lattice constants are reported for the five complexes with aromatic solvents and TNF. The complexes of TCVDMA with benzene, toluene, and chlorobenzene have the stoichiometry 2TCVDMA (aromatic) and similar lattice constants. The complexes of TCVDMA with DMA and 1,2,4-trichlorobenzene have the unusual stoichiometry 4TCVDMA (aromatic) with similar lattice constants including a short unit cell dimension of ca. 4. 0 A. The complexes with DMA, TNF, and p-chloranil are found to have new absorption assigned to charge-transfer transitions and are thus Mulliken donor-acceptor complexes. Based on molecular energy levels and redox potentials, TCVDMA behaves as a donor in its complexes with TNF and p-chloranil and as an acceptor in its complex with DMA. Thus TCVDMA is the first example of a molecule to yield well-defined solid complexes in which it behaves as a donor with one molecule and as an acceptor with another. While TCVDMA has long been known to be a solvatochromic, its solvent shifts do not give good correlations with E//T* and Z. The most quantitative correlation found was between the frequency shift and a refractive index function for the solvents benzene, toluene, and chlorobenzene. The sensitivity of the spectra of solid evaporated films of TCVDMA to degree of crystallinity thermal history, and exposure to benzene vapor is reported. A recent claim that p-dimethylaminobenzylidenemalononitrile, a moleculel similar in structure to TCVDMA, gave different crystalline forms on crystallization from benzene and methanol was found not to be reproducible.
