The reactions of [Pt(CO)] (n = 2-4) homoleptic Chini-type clusters with stoichiometric amounts of PhPCHCHPPh (dppe) result in the heteroleptic Chini-type clusters [Pt(CO)(dppe)], [Pt(CO)(dppe)], and [Pt(CO)(dppe)]. Their formation is accompanied by slight amounts of neutral species such as Pt(CO)(dppe), Pt(CO)(dppe), and Pt(dppe). A similar behavior was observed with the chiral ligand R-PhPCH(Me)CHPPh (R-dppp), and two isomers of [Pt(CO)(R-dppp)] were identified. All the new species were spectroscopically characterized by means of IR and P NMR, and their structures were determined by single-crystal X-ray diffraction. The results obtained are compared to those previously reported for monodentate phosphines, that is, PPh, as well as more rigid bidentate ligands, that is, CH═C(PPh) (P^P), CH(PPh) (dppm), and o-CH(PPh) (dppb). From a structural point of view, functionalization of anionic platinum Chini clusters preserves their triangular Pt units, whereas the overall trigonal prismatic structures present in the homoleptic clusters are readily deformed and transformed upon functionalization. Such transformations may be just local deformations, as found in [Pt(CO)(dppe)], [Pt(CO)(R-dppp)], [Pt(CO)(PPh)], and [Pt(CO)(PPh)]; an inversion of the cage from trigonal prismatic to octahedral, as observed in [Pt(CO)(dppe)] and [Pt(CO)(PPh)]; the reciprocal rotation of two trigonal prismatic units with the loss of a Pt-Pt contact as found in [Pt(CO)(dppe)].

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The reaction of [Ni6(CO)12]2– as a [NBu4]+ salt in CH2Cl2 with 0.8 equiv of PCl3 afforded [Ni14P2(CO)22]2–. In contrast, the reactions of [Ni6(CO)12]2– as a [NEt4]+ salt with 0.4–0.5 equiv of POCl3 afforded [Ni22–x P2(CO)29–x ]4– (x = 0.84) or [Ni39P3(CO)44]6– by using CH3CN and thf as a solvent, respectively. Moreover, by using 0.7–0.9 mol of POCl3 per mole of [NEt4]2[Ni6(CO)12] both in CH3CN and thf, [Ni23–x P2(CO)30–x ]4– (x = 0.82) was obtained together with [Ni22P6(CO)30]2– as a side product. [Ni23–x P2(CO)30–x ]4– (x = 0.82) and [Ni22P6(CO)30]2– were separated owing to their different solubility in organic solvents. All the new molecular nickel phosphide carbonyl nanoclusters were structurally characterized through single crystal X-ray diffraction (SC-XRD) as [NBu4]2[Ni14P2(CO)22] (two different polymorphs, P21/n and C2/c), [NEt4]4[Ni23–x P2(CO)30–x ]·CH3COCH3·solv (x = 0.82), [NEt4]2[Ni22P6(CO)30]·2thf, [NEt4]4[Ni22–x P2(CO)29–x ]·2CH3COCH3( x = 0.84) and [NEt4]6[Ni39P3(CO)44]·C6H14·solv. The metal cores’ sizes of these clusters range from 0.59 to 1.10 nm, and their overall dimensions including the CO ligands are 1.16–1.63 nm. In this respect, they are comparable to ultrasmall metal nanoparticles, molecular nanoclusters, or atomically precise metal nanoparticles. The environment of the P atoms within these molecular Ni–P–CO nanoclusters displays a rich diversity, that is, Ni5P pentagonal pyramid, Ni7P monocapped trigonal prism, Ni8P bicapped trigonal prism, Ni9P monocapped square antiprism, Ni10P sphenocorona, Ni10P bicapped square antiprism, and Ni12P icosahedron.

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ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.