Crystal structures of six complexes of phosphane chalcogenides P ( = -butyl or isopropyl, = S or Se) with the metal halides ( = Pd or Pt, = Cl or Br), two halochalcogenyl-phospho-nium derivatives ( Bu PrPBr)[PdBr] and one hydrolysis product.

The complexes - (: = BuPrPSe, = Pd, = Cl; : = Bu PrPSe, = Pd, = Cl; : = Bu PrPSe, = Pd, = Br; : = Bu PrPS, = Pd, = Br; : = Bu PrPS, = Pt, = Cl) {systematic names: (-butyl-diiso-propyl-phosphine selenide-κ)di-chlorido-palladium(II), [PdCl(CHPSe)] (), (di--butyl-iso-propyl-phosphine selenide-κ)di-chloridopalladium(II), [PdCl(CHPSe)] (), di-bromido-(di--butyl-iso-propyl-phosphine selenide-κ)palladium(II), [PdBr(CHPSe)] (), di-bromido-(di--butyl-iso-propyl-phosphine sulfide-κ)palladium(II), [PdBr(CHPS)] (), di-chlorido-(di--butyl-iso-propyl-phosphine sulfide-κ)palladium(II), [PdCl(CHPS)] ()} all display a configuration with square-planar geometry at the metal atom. Compounds and are isotypic. The mol-ecules of and display crystallographic inversion symmetry; compound involves two independent mol-ecules, each with inversion symmetry but with differing orientations of the tri-alkyl-phosphane groups. Chemically equivalent bond lengths all lie in narrow ranges, whereby the values for palladium and platinum compounds scarcely differ. Compound , ( BuPrPS)PdCl {systematic name: di-μ-chlorido-bis-[(-butyldiiso-propyl-phosphine sulfide-κ)chlorido-palladium(II)], [PdCl(CHPS)]}, is dinuclear with a central PdCl ring, and displays crystallographic inversion symmetry. The bonds to the bridging are longer than those to the terminal chlorine atoms; the Pd-S bond is shorter than the -S bonds in and , reflecting the weaker influence of (bridging) chlorine compared to sulfur. Compounds and , 2( Bu PrPBr) [PdBr] with = S for and Se for {systematic names: (bromo-sulfan-yl)di--butyl-iso-propyl-phosphanium di-μ-bromido-bis-[di-bromido-palladium(II)], (CHBrPS)[PdBr] () and (bromo-selan-yl)di--butyl-iso-propyl-phosphanium di-μ-bromido-bis-[di-bromido-palladium(II)], (CHBrPS)[PdBr], ()}, were obtained by oxidizing the appropriate Pd precursors with elemental bromine; they are not isotypic. The ions are connected by very short halogen bonds Br⋯Br. For both compounds, two ⋯Br contacts further link the cations and anions to form ribbons. Compound {systematic name: bis-[dimeth-yl(sulfanyl-idene)phosphin-ito-κ]bis-(hy-droxy-diiso-propyl-phosphine selenide-κ)palladium(II), [Pd(CHOP)(CHOP)], {(PrPSeO)H}Pd, is a hydrolysis product with inversion symmetry and contains an intra-molecular P-O⋯H-O-P group with a disordered hydrogen atom. Compounds - and show few, if any, short inter-molecular contacts, although some H⋯ contacts are observed. A problem with atom-type assignment for structure refinement is discussed.