Anthony D. Miles

Bio: Anthony D. Miles is an academic researcher from University of Bristol. The author has contributed to research in topics: Crystal structure & Cluster (physics). The author has an hindex of 4, co-authored 4 publications receiving 88 citations.

Synthesis of tetra-and penta-nuclear platinum–osmium carbido-cluster complexes from non-carbido-precursors: X-ray structural studies on [Os3Pt (µ-H)2(µ4-C)(CO)10{P(cyclo-C6H11)3}],[Os3Pt2(µ-H)2(µ5-C)(µ-CO)(CO)9{P(cyclo-C6H11)3}2], and [Os3Pt2(µ-H)(µ5-C)(µ-OMe)(µ-CO)(CO)9{P(cyclo-C6H11)3}2]

Abstract: The reaction between the compounds [Os3(µ-H)(µ3-CH)(CO)10] and [Pt(C2H4)2{P(cyclo-C6H11)3}] in toluene at 80 °C affords two cluster complexes, one containing a single platinum atom [Os3Pt(µ-H)2(µ4-C)(CO)10{P(C6H11)3}](1), and the other two platinum atoms, [Os3Pt2(µ-H)2(µ4-C)(µCO)(CO)9{P(C6H11)3}2](2) Both have been characterised by single-crystal X-ray diffraction studies Compound (1) contains a triangle of osmium atoms [Os–Os 2828(1)–2906(1)A], with the Pt atom bonded to one osmium [Os(2)–Pt 2764(1)A] The carbido-carbon atom is irregularly bonded [190(2)–221(2)A] to all four metal atoms Each osmium atom is ligated by three terminal carbonyl ligands, whilst the platinum atom is bonded to a terminal carbonyl group and a P(cyclo-C6H11)3 moiety Two hydrido-ligands bridge the Os(1)–Os(3) and Os(1)-Os(2) vectors Compound (2) contains a square-planar arrangement comprising two osmium and two platinum atoms with the third osmium atom [Os(3)] bridging the Os(1)–Os(2) edge The angle between the planes Os(1)Os(2)Pt(1)Pt(2) and Os(1)Os(2)Os(3) is 764° The carbido-carbon atom is approximately equidistant [2065(11)T–2120(10)A] from all five metal atoms, and the metal–metal separations are Os–Os 2855(1)–2917(1), Os–Pt 2929(1)–2935(1), and Pt(1)–Pt(2) 2716(1)A Each osmium atom carries three terminal carbonyl ligands, whilst the platinum atoms are symmetrically bridged by a carbonyl ligand, and each is ligated by a P(cyclo-C6H11)3 group The two hydrido-ligands bridge equivalent edges [Os(1)–Os(3) and Os(2)–Os(3)] The nmr data (1H, 13C-{1H}, and 31P-{1H}) are all consistent with the structures established in the solid state Treatment of [Pt(C2H4)2{P(cyclo-C6H11)3}] with [Os3(µ-H)(µ-COMe)(CO)10] in toluene at ambient temperatures affords a pentanuclear metal complex [Os3Pt2(µ-H)(µ5-C)(µ-OMe)(µ-CO)(CO)9{P(C6H11)3}2](3), the structure of which was again determined by single-crystal X-ray diffraction Two platinum and two osmium atoms are arranged in a ‘buckled’ square with the third osmium atom [Os(3)] metal–metal bonded only to Os(1) As in (2), the carbido–metal distances are approximately equal [2075(22)–2144(20)A] Moreover, the metal–metal distances Os–Os [2813(1)–2853(1)A] and Os–Pt [2891(1)–2941(1)A] are rather similar to those in (2) but the Pt–Pt distance [2668(1)A] is noticeably shorter In (3) each osmium atom carries three terminal carbonyl ligands, while a single carbonyl group asymmetrically bridges the two platinum atoms [Pt–µ-CO 2032(23) and 1968(20)A] Each platinum bears a P(cyclo-C6H11)3 group, with the hydrido-ligand bridging the shorter of the two Pt–Os edges [Pt(1)–Os(1)] The nmr spectra are consistent with the structure established in the solid state though some dynamic behaviour is evident

Bis(ethylene)(η-pentamethylcyclopentadienyl)cobalt as a precursor to heteronuclear metal clusters: X-ray crystal strucutre of [Co2Mo2(µ-CO)3lpar;µ4-CO)(η-C5H5)2(η-C5Me5)2]; a model for CO activation on a stepped metal surface

Abstract: U.v irradiation of [Co(C2H4)2(η-C5Me5)] with the compounds [M2(CO)4(η-C5R5)2](M = Fe or Ru, and R = H; M = Fe, R = Me) or [Mo2(CO)4(η-C5H5)2] affords the clustesr complexes [CoM2(µ-CO)3(µ3-CO)-(η-C5Me5)(η-C5R5)2] and [Co2Mo2(µ-CO)3(µ4-CO)(η-C5H5)2(η-C5Me5)2]; the molecular structure of the latter species, established by X-ray diffraction, reveals a novel bonding mode for a CO ligand.

The synthesis of some bi- and tri-metallic clusters containing rhodium; X-ray crystal structures of [MoRh3(µ3-CO)3(CO)3(PPh3)3(η-C5H5)]·CH2Cl2 and [MoRhPt(µ-CO)2(µ-PPh2)(µ-1-σ:1–2-η-C6H5)-(PPh3)2(η-C5H5)]

Abstract: Treatment of the complexes [MRh(µ-CO)2(CO)(PPh3)2(η-C5H5)](M = Mo or W) with [Fe2(CO)9] in tetrahydrofuran at room temperature affords the tetranuclear 56 valence-electron cluster compounds [MRh3(µ3-CO)3(CO)3(PPh3)3(η-C5H5)]. The structure of the molybdenumtrirhodium species, which crystallises with a molecule of CH2Cl2, has been established by a single-crystal X-ray diffraction study. The metal-atom core approximates to a regular tetrahedron, with Rh–Rh separations 2.710(1)–2.729(1)A, and Mo–Rh distances 2.764(1)–2.778(1)A. The molybdenum atom carries the η-C5H5 ligand, and a CO and a PPh3 group are attached to each rhodium atom. These terminal carbonyl ligands are directed below the Rh3 triangle, and the three ligated phosphorus atoms lie above. In addition, a CO group triply bridges each of the MoRh2 faces of the cluster. The reaction between [MoRh(µ-CO)2(CO)(PPh3)2(η-C5H5)] and [Pt(C2H4)(PPh3)2] in tetrahydrofuran at 50 °C yields the complexes [MoPt(µ-PPh2)(CO)2(PPh3)2(η-C5H5)] and [MoRhPt(µ-CO)2(µ-PPh2)(µ-1-σ:1–2-η-C6H5)(PPh3)2(η-C5H5)]. The structure of the 44 valence-electron trimetal compound has been determined by X-ray diffraction. The three metal atoms form a triangle [Mo–Pt 2.958(1), Mo–Rh 2.619(1), and Pt–Rh 2.662(1)A], the molybdenum atom carries the η-C5H5 ligand, and the platinum and rhodium atoms are co-ordinated by PPh3 groups. The three edges of the metal triangle are bridged; the Mo–Rh edge by two CO ligands, the Mo–Pt by PPh2, and the Rh–Pt by a C6H5 group. One carbon of the phenyl group is σ bonded to platinum and together with an adjacent carbon is η2-co-ordinated to the rhodium. The n.m.r. data (1H, 13C-{1H}, and 31P-{1H}) for the new compounds are reported and discussed.

Intramolecular d10–d10 interactions in heterometallic clusters of the transition metals

Abstract: Weak attractive interactions between closed shell metal ions have been increasingly studied in the last few years and are generally designated as metallophilic interactions. They are best evidenced in the solid state where structural data obtained by X-ray diffraction provide precise information about the distance between the metals involved. The strength of such metal–metal interactions has been compared to that of hydrogen bonding (ca. 7–11 kcal mol−1) and is clearly sufficient to bring about novel bonding and structural features and confer interesting physical properties such as luminescence, polychromism, magnetism or one-dimensional electrical conductivity. The Cu(I)–Cu(I), Ag(I)–Ag(I) and Au(I)–Au(I) interactions have been increasingly observed and the latter have certainly been the most studied. Early qualitative analyses of the aurophilic attraction focused on Au–Au bonding originating from 6s, 6p and 5d orbital mixing. Numerous theoretical studies on metallophilic interactions continue to be carried out at various levels of sophistication which take into account relativistic and correlation effects to describe these van der Waals-type interactions. In this critical review, we would like to focus on the synthesis and structures of heterometallic clusters of the transition metals in which intra- rather than intermolecular d10–d10 interactions are at work, in order to limit the role of packing effects. We wish to provide the reader with a comparative overview of the metal core structures resulting from or favoring metallophilic interactions but do not intend to provide a comprehensive coverage of the literature. We will first examine heterometallic clusters displaying homometallic and then heterometallic d10–d10 interactions. Although the focus of this review is on d10–d10 interactions involving metals from the group 11, we shall also briefly examine for comparison some complexes displaying intramolecular d10–d10 interactions involving metals from other groups (188 references).

C- and O-Bonded Metal Carbonyls: Formation, Structures, and Reactions

Abstract: Publisher Summary Metal carbonyls, which were among the earliest discovered organometallic compounds, continue to play a central role in organometallic chemistry. Carbonyl basicity is found for C-bridging CO ligands in metal–metal bonded compounds, CO ligands in anionic metal carbonyls, or CO ligands in donor-substituted metal carbonyls. The interaction of protons with mononuclear metal carbonyls readily occurs at the metal center rather than the CO oxygen; no stable or transient MCO–H species appear to have been observed. The chemical and structural characterization of molecular compounds containing π–CO is of great interest, because the π–CO is implicated as a precursor to the cleavage of CO on metal surfaces, such as those employed in Fischer–Tropsch catalysis. In view of these large physical changes, it perhaps is not surprising that C and O bonding also engenders large changes in CO reactivity. Carbon monoxide insertion into a metal–alkyl bond is a fundamental reaction in organometallic chemistry as well as an important step in the commercial production of oxygen-containing organics, such as aldehydes and acetic acid.

The Interface of Main Group and Transition Metal Cluster Chemistry

Abstract: The literature concerning cluster complexes which contain both main group element and transition metal vertices is reviewed. Synthetic methods and general reactivity patterns are summarized. Emphasis is placed on structural. Comparisons of cluster geometries for a wide variety of element combinations. Relationships between these mixed clusters and the main group element clusters known as Zintl ions are discussed.