The donor-acceptor complexes PPh(4)[Cl(succinimide)(2)] and PPh(4)[Cl(N-chlorosuccinimide)(2)] have been prepared by reactions of PPh(4)Cl with succinimide and N-chlorosuccinimide, respectively, in acetonitrile solutions. The complexes have been characterized by IR spectroscopy and by crystal structure determinations. The crystal structure of N-chlorophthalimide has also been solved. N-chlorophthalimide: Space group P2(1)2(1)2(1), Z = 4, 941 observed unique reflections, R = 0.025. Lattice dimensions at -50 degrees C: a = 572.8(1), b = 627.5(1), c = 2072.5(2) pm. The compound has a molecular structure with intermolecular Cl...O-contacts of 294.6(2) pm. PPh(4)[Cl(succinimide)(2)]: Space group C222(1), Z = 8, 1643 observed unique reflections, R = 0.048. Lattice dimensions at -40 degrees C: a = 976.7(1), b = 2471.0(3), c = 1472.2(3) pm. The structure consists of PPh(4)(+) ions and anions [Cl(succinimide)(2)](-), in which the chloride ion is coordinated to the nitrogen bonded hydrogen atoms of the succinimide molecules with bond angles N-H...Cl of 177(2)degrees and H...Cl...H of 124.6(6)degrees. PPh(4)[Cl(N-chlorosuccinimide)(2)]: Space group P2(1)/n, Z = 4, 2519 observed unique reflections, R = 0.045. Lattice dimensions at -70 degrees C: a = 1761(2), b = 753.4(7), c = 2318(2) pm, beta = 100.98(7)degrees. The structure consists of PPh(4)(+) ions and anions [Cl(N-chlorosuccinimide)(2)](-), in which the chloride ion is coordinated by the chlorine atoms of the N-chlorosuccinimide molecules with bond lengths N-Cl of 174.1(4) and Cl...Cl 289.5(3) pm, and bond angles of N-Cl...Cl of 177.8(1)degrees and Cl...Cl...Cl of 85.24(6)degrees (average).