Zwitterion formation in titan ice analogs: reaction between HC3N and NH3.

A zwitterion is formed in the laboratory at low temperatures in the solid phase from the thermal reaction of HC(3)N and NH(3). We report for the first time its infrared spectrum. We study its reaction using Fourier transform infrared spectroscopy.

2-Oxo-2H-chromen-4-yl 4-tert-butyl-benzoate.

In the title mol-ecule, C(20)H(18)O(4), the three methyl groups of the tert-butyl substituent show rotational disorder. Each methyl group is split over three positions, with refined site-occupation factors of 0.711 (4), 0.

4-[(4-Chloro-phen-yl)(hy-droxy)methyl-idene]isochromane-1,3-dione.

In the title compound, C(16)H(9)ClO(4), the six-membered heterocyclic ring adopts a screw-boat conformation. The benzene rings are oriented to each other at a dihedral angle of 59.26 (9)°.

2-Oxochromen-4-yl 4-(dimethyl-amino)-benzoate.

In the title mol-ecule, C(18)H(15)NO(4), the benzoate ring is oriented at a dihedral angle of 43.43 (6)° with respect to the planar [maximum deviation = 0.038 (2) Å] chromene ring.

An axial tert-butyl group in strained cyclohexene: X-ray analysis and theoretical calculations of 2-(2-tert-butylcyclohex-3-enyl)propan-2-ol.

The structure of the title compound, C(13)H(24)O, (I), shows a sofa conformation of the ring with two pseudo-axial substituents. The dihedral angle between these substituents is 131.56 (12) degrees .