The crystal structures of two salts with large multi-atom ions: diphenyliodonium nitrate and isobutylammonium monoacidbis-[N, N'-bis(isobutyl)diamidodiselenophosphate]

Abstract

The structure of diphenyliodonium nitrate, (C₆H₅)₂INO₃, has been determined from X-ray single-crystal diffractometer data. The crystals are orthorhombic, space group Fdd2. The unit-cell constants are: a = 31.906(6), b = 12.719(3), c = 12.059(3) A at 22°C, Z = 16. The I atom is surrounded by two C and two O atoms in a planar configuration. The I to ring distances are I-C1, 2.116(7) and I-C7, 2.114(9) A. O2 is 2.768(8) A from I and O2' is 2.877(8) A. These O atoms occupy equivalent positions in different nitrate groups. Atomic and thermal vibrational parameters were refined by an isotropic least-squares methods. The C1-I-C7 angle is 92.0(4)°. The final value of the discrepancy index, R, was R = 0.036, with H atoms included. Isobutylammonium monoacidbis[N,N'-bis(isobutyl)diamidodiselenophosphate] crystallizes in a triclinic unit cell space group I1. Cell constants are a = 19.993, b = 15.895, and c = 11.270 A. Atomic positions for P and Se have been determined by standard Fourier methods. Within the molecule each phosphorus atom is tetrahedrally surrounded by two selenium and two light atoms (nitrogen or carbon). Due to decomposition and absorption effects it was impossible to determine all light atom positions from the film data available.