CRYSTAL-STRUCTURES AND BONDING IN NOCL, NO2CL, AND NO3CL

The crystal structures of NOCl, NO2Cl, and NO3Cl have been determined. NOCl forms a high-temperature phase (Cmcm, a = 413.2(1) pm, b = 1082.9(3) pm, c = 546.1(1) pm at -125 degrees C) with the NO moiety showing 2-fold disorder while in the low-temperature modification (Pnma, a = 1085.6(2) pm, b = 539.93(9) pm, c = 406.63(8) pm at -160 degrees C) continuous ordering is observed. The structure of the molecule is remarkably different in the solid state as compared to the gas phase. NO2Cl crystallizes in the triclinic system (P (1) over bar, a = 543.1(1) pm, b = 737.4(1) pm, c = 758.1(1) pm, alpha = 72.39(1)degrees, beta = 78.88(2)degrees, gamma = 89.56(2)degrees at -170 degrees C) with two crystallographically independent molecules in the asymmetric unit. NO3Cl is best described as an adduct of the radicals NO2 and ClO (P2(1)2(1)2(1), a = 385.6(1) pm, b = 675.5(2) pm, c = 1207.6(3) pm at -166 degrees C).