This work comprised the preparation of six complexes of Ni(II) and their study by spectroscopy and X-ray diffraction. These complexes are: [Ni(dppe)Cl 2 ]CH 2 Cl 2 (I), [Ni(dppen)Cl 2 ] (II), [Ni(dppm)Br 2 ]CH 2 Cl 2 (III), [Ni(dppe)(NCS) 2 ] (IV), [Ni(dppen)I 2 ] (V), [Ni(dppp)Cl 2 ]CH 2 Cl 2 (VI), where dppe=1,2-bis(diphenylphosphine)ethane, dppen=cis-1,2-bis(diphenylphosphine)ethene, dppm=bis(diphenylphosphine)methane, dppp=1,3-bis(diphenylphosphine)propane. The structures of complexes III-VI are unknown in the literature. Although the molecular structures of the six complexes present many similarities, their crystalline arrangements vary considerably. This is a feature not presented hitherto in previous work involving complexes of this type. In addition, a systematic spectroscopic study was undertaken on all six complexes.