The structure of 4-(N,N-dimethylamino)benzonitrile and its van der Waals complexes

Twisted intramolecular charge transfer states: Rotationally resolved fluorescence excitation spectra of 4,4′-dimethylaminobenzonitrile in a molecular beam

“…The ground state values compare favorably with the earlier microwave values. 9 Typically, microwave values are more precise, but in this case only eight pure rotational transitions were measured, making the precision in our experiment at least as high as the microwave one. Individual lines identified in the fitting process have full widths at half maxima of about 50 MHz.…”

“…A simulated spectrum of this subband was generated using the previously measured rotational constants of the ground state 9 and CIS 6-31+ G values for the excited state. This was sufficient to reproduce its main features.…”

“…Our best-fit structure has an inversion angle of 18.5°a nd an angle between the methyl groups of 122°, giving ⌬I = −7.54 amu Å 2 as shown in Table IV. Earlier microwave studies 9 estimated an inversion angle of 15°. The corresponding angle in the ground state of aniline is ϳ38°.…”

“…8 Significant activity of several vibrational modes lying within the first 200 cm −1 of the origin was detected in both the excitation and emission spectra and attributed to both DMA inversion and twisting motions. Kajimoto et al 9 measured the microwave spectrum of DMABN and found the ground state to be nearly planar with an inversion angle of about 15°. They also observed a partially resolved rotational band contour of the S 1 -S 0 electronic spectrum of DMABN and concluded that, in the S 1 state, the DMA group is rotated by 30°from the aromatic plane.…”

Ground State 14N Quadrupole Couplings in the Microwave Spectra of N,N′-Dimethylaniline and 4,4′-Dimethylaminobenzonitrile

“…In addition, the splittings of the nitrile group in DMABN should be similar to those of benzonitrile, which have been observed by Grabow and co-workers. 8 Reported here are studies of the microwave spectra of DMA (6-18 GHz) and DMABN (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18) in the collision-free environment of a supersonic jet. Broadband experiments were performed to determine substitution structures of both molecules from the spectra of all 13 C-and 15 N-substituted isotopologues in natural abundance.…”