화학공학소재연구정보센터
Journal of Physical Chemistry A, Vol.103, No.51, 11460-11464, 1999
Structure and conformation of furfurylamine determined by gas-phase electron diffraction, microwave spectroscopy data, and ab initio molecular orbital calculations
The structure and conformation of furfurylamine, C4H4OCH2NH2, were determined by gas-phase electron diffraction augmented by rotational constants from microwave spectroscopy taken from the literature, and by results from theoretical calculations. A mixture of two conformers with different C=C-C-N torsion angles, phi, was observed. At 298 K the majority of the molecules (87(2 sigma=9)%) had a gauche (skew) conformation with phi = 114(1)degrees, and the rest of the molecules had a syn conformation where the C-N bond is eclipsing the carbon-carbon double bond of the furan ring (phi = 0 degrees). Both these conformers may be stabilized by hydrogen bonds between the amine hydrogen atoms and the oxygen of the furan ring and/or the pi-electrons of the carbon-carbon double bond. The experimental bond distances and bond angles (r(pi)(0)/r(g) and angle(alpha)), with estimated 2 sigma uncertainties (sigma include estimates of systematic errors and correlation in the experimental data) are as follows: r(N-H) = 1.022/1.046(6) Angstrom, r(C-H) = 1.092/1.109(5) Angstrom, r(O-C) = 1.359/1.361(8) Angstrom, r(C=C) = 1.365/1.368(8) Angstrom, r(=C-C=) = 1.453/1.456(5) Angstrom, r(C-C) = 1.491/1.493(8) Angstrom, r(C-N) = 1.470/1.474(7) Angstrom, angle C-C-N = 114.1(6)degrees, angle C-6-C-2=C-3 = 133.0(7)degrees, angle C-O-C = 108.4(10)degrees angle O-C=C = 109.8(5)degrees, angle C-2-C-3=C-4 = 106.3(2)degrees.