Single crystal X-ray structure determinations have been executed for several title compounds of the mononuclear form [LMX2], namely [(bpy)ZnX2], X = Cl, Br; [(phen)ZnX2], X = Cl, Br, I (bpy = 2,2′-bipyridine; phen = 1,10-phenanthroline). Also reported are the crystal structures of ZnSO4/bpy/H2O (1: 1: 5) (≡ [(bpy)Zn(OH2)4](SO4)·H2O) and Zn(NO3)2/bpy/H2O (1: 1: 3) (≡ [(bpy)Zn(OH2)3(ONO2)](NO3)). The sulfate complex completes the array [LM(OH2)4]2+, L = bpy, phen, M = Zn, Cd, while the nitrate is the first nitrate example for [LM(OH2)3(OX)](+) (OX = ONO2, OSO3). In all examples of the sulfate and nitrate forms here and previously defined, the metal atoms are six-coordinate, with any anionic donors lying in axial coordination sites (i.e. M-O (quasi-) normal to the LM plane). The structures of [LHg(SCN)2] (L = phen, tpy) (tpy = 2,2′:6′,2′-terpyridine), [(tpy)(CdBr2], and [Zn(tpy)2](NO3)2·2H2O are also recorded.