Showing papers by "Richard D. Adams published in 2005"

Addition of palladium and platinum tri-tert-butylphosphine groups to Re-Sn and Re-Ge Bonds

Abstract: The reaction of Re2(CO)8[μ-η2-C(H)C(H)Bun](μ-H) with Ph3SnH at 68 °C yielded the new compound Re2(CO)8(μ-SnPh2)2 (10) which contains two SnPh2 ligands bridging two Re(CO)4 groups, joined by an unusually long Re−Re bond. Fenske−Hall molecular orbital calculations indicate that the bonding in the Re2Sn2 cluster is dominated by strong Re−Sn interactions and that the Re−Re interactions are weak. The 119Sn Mossbauer spectrum of 10 exhibits a doublet with an isomer shift (IS) of 1.674(12) mm s-1 and a quadrupole splitting (QS) of 2.080(12) mm s-1 at 90 K,characteristic of Sn(IV) in a SnA2B2 environment. The IS is temperature dependent, −1.99(14) × 10-4 mm s-1 K-1; the QS is temperature independent. The temperature-dependent properties are consistent with the known Gol'danskii−Kariagin effect. The germanium compound Re2(CO)8(μ-GePh2)2 (11) was obtained from the reaction of Re2(CO)8[μ-η2-C(H)C(H)Bun](μ-H) with Ph3GeH. Compound 11 has a structure similar to that of 10. The reaction of 10 with Pd(PBut3)2 at 25 °C y...

New Rhenium--Tin Cluster Adds Palladium Phosphine Groups across Re--Sn Bonds

Abstract: The new rhenium−tin complex Re2(CO)8(μ-SnPh2)2, 1 was obtained in 52% yield from the reaction of Re2(CO)8(μ-H)[μ-C(H)C(H)Bu] with Ph3SnH. Compound 1 contains two SnPh2 groups bridging a long Re−Re single bond, Re−Re = 3.1971(4) A [3.1902(4) A], Re−Sn = 2.7429(4) A [2.7445(4) A], and 2.7675(4) [2.7682(5) A]. A bis-Pd(PBut3) adduct of 1, Pd2Re2(CO)8(μ-SnPh2)2(PBut3)2, 2 was obtained from the reaction of 1 with Pd(PBut3)2. Compound 2 contains Pd(PBut3) groups bridging two of its four Re−Sn bonds. The Re−Re bond and the unbridged Re−Sn bonds in 2 are significantly longer than those in 1, 3.245(1) A and 2.8167(14) A, respectively. Fenske−Hall molecular orbital calculations on 1 and 2 have been performed to explain the metal−metal bonding in these unusual mixed-metal polynuclear metal complexes.

High-nuclearity iridium carbonyl clusters containing phenylgermyl ligands: synthesis, structures, and reactivity.

Abstract: The reaction of Ir 4 (CO) 1 2 with Ph 3 GeH at 97 °C has yielded the new tetrairidium cluster complexes Ir 4 (CO) 7 -(GePh 3 )(μ-GePh 2 ) 2 [μ 3 -η 3 -GePh(C 6 H 4 )](μ-H) 2 (10) and Ir 4 (CO) 8 (GePh 3 ) 2 (μ-GePh 2 ) 4 (11). The structure of 10 consists of a tetrahedral Ir 4 cluster with seven terminal CO groups, two bridging GePh 2 ligands, an ortho-metallated bridging μ 3 -η 3 -GePh(C 6 H 4 ) group, a terminal GePh 3 ligand, and two bridging hydrido ligands. Compound 11 consists of a planar butterfly arrangement of four iridium atoms with four bridging GePh 2 and two terminal GePh 3 ligands. The same reaction at 125 °C yielded the two new triiridium clusters lr3(CO)5(GePh3)(μ-GePh 2 ) 3 (μ 3 -GePh)(μ-H) (12) and Ir 3 (CO)6(GePh3) 3 (μ-GePh2)3 (13). Compound 12 contains a triangular Ir 3 cluster with three bridging GePh 2 , one triply bridging GePh, and one terminal GePh 3 ligand. The compound also contains a hydrido ligand that bridges one of the Ir-Ge bonds. Compound 13 contains a triangular Ir 3 cluster with three bridging GePh 2 and three terminal GePh 3 ligands. At 151 °C, an additional complex, lr4H4(CO) 4 (μ-GePh2) 4 (μ 4 -GePh)2 (14), was isolated. Compound 14 consists of an Ir 4 square with four bridging GePh 2 , two quadruply bridging GePh groups, and four terminal hydrido ligands. Compound 12 reacts with CO at 125 °C to give the compound Ir 3 (CO) 6 (μ-GePh 2 ) 3 (μ 3 -GePh) (15). Compound 15 is formed via the loss of the hydrido ligand and the terminal GePh 3 ligand and the addition of one carbonyl ligand to 12. All compounds were fully characterized by IR, NMR, single-crystal X-ray diffraction analysis, and elemental analysis.

High nuclearity iridium-platinum clusters: synthesis, structures, bonding, and reactivity.

Abstract: The reaction of Ir4(CO)12 with an excess of Pt(PBut3)2 at room temperature yielded the bis-Pt(PBut3) adduct Ir4(CO)12[Pt(PBut3)]2 (9), which contains two Pt(PBut3) groups bridging opposite edges of a central Ir4 pseudotetrahedron. The same reaction at 110 °C yielded two new higher nuclearity complexes, Ir8(CO)12[Pt(PBut3)]4 (10) and Ir6(CO)10[Pt(PBut3)]4 (11). Compound 10 consists of a central Ir4(CO)4 tetrahedron with four edge-bridging Ir(CO)2 groups and four Pt(PBut3) groups that are each bonded to Ir3 triangles of the Ir4 tetrahedron and two of the Ir(CO)2 groups. Compound 11 consists of a central Ir4(CO)4 pseudotetrahedron with two edge-bridging Ir(CO)2 groups and four Pt(PBut3) groups; one Pt(PBut3) group is bonded to five iridium atoms as found in 10; two are bonded to four iridium atoms, and one is bonded to one of the outer Ir2Pt triangles. Compound 11 reacted with hydrogen at 97 °C to give the new tetrahydrido complex Ir6(CO)8[Pt(PBut3)]4(μ-H)4 (12). Compound 12 is formed by the loss of the two ...

Synthesis of PtRu5(CO)14(PBut3)(μ-H)2(μ6-C) and Its Reactions with Pt(PBut3)2, HGePh3, and HSnPh3

Abstract: Reaction of PtRu 5 (CO) 1 5 (PBu t 3 )(C), 3, with hydrogen at 97 °C yielded the new dihydride-containing cluster compound PtRu 5 (CO) 1 4 (PBu t 3 )(μ-H) 2 (μ 6 -C), 5. Compound 5 was characterized crystallographically and was shown to contain an octahedral cluster consisting of one platinum and five ruthenium atoms with a carbido ligand in the center. Two hydrido ligands bridge two oppositely positioned PtRu bonds. Compound 5 reacts with Pt(PBu t 3 ) 2 to yield Pt 2 Ru 5 -(CO) 1 4 (PBu t 3 ) 2 (μ-H) 2 (μ 6 -C), 6, a Pt(PBu t 3 ) adduct of 5, by adding a Pt(PBu t 3 ) group as a bridge across one of the Ru-Ru bonds in the square base of the Ru 5 portion of the cluster. Compound 6 is dynamically active on the NMR time scale by a mechanism that appears to involve a shifting of the Pt(PBu t 3 ) group from one Ru-Ru bond to another. Two new complexes, PtRu 5 (CO) 1 3 (PBu t 3 )(μ-H) 3 (GePh 3 )(μ 5 -C), 7, and PtRu 5 (CO) 1 3 (PBu t 3 )(μ-H) 2 (μ-GePh 2 )-(μ 6 -C), 8, were obtained from the reaction of 5 with HGePh 3 . The cluster of 7 has an open structure in which the Pt(PBu t 3 ) group bridges an edge of the square base of the square pyramidal Ru 5 cluster. Compound 7 also has three bridging hydrido ligands and one terminal GePh 3 ligand. When heated to 97 °C, 7 is slowly converted to 8 by cleavage of a phenyl group from the GePh 3 ligand and elimination of benzene by its combination with one of the hydrido ligands. The PtRu 5 metal cluster of 8 has a closed octahedral shape with a GePh 2 ligand bridging one of the Ru-Ru bonds. Two tin-containing compounds, PtRu 5 (CO) 1 3 (PBu t 3 )(μ-H) 3 (SnPh 3 )(μ 5 -C), 9, and PtRu 5 (CO) 1 3 -(PBut 3 )(μ-H) 2 (μ-SnPh 2 )(μ 6 -C), 10, which are analogous to 7 and 8 were obtained from the reaction of 5 with HSnPh 3 .

Rhodium cluster complexes containing bridging phenylgermanium ligands.

Abstract: The reaction of Rh4(CO)12 with Ph3GeH at 97 °C has yielded the first rhodium cluster complexes containing bridging germylene and germylyne ligands: Rh8(CO)12(μ4-GePh)6, 9, and Rh3(CO)5(GePh3)(μ-GePh2)3(μ3-GePh)(μ-H), 10. When the reaction is performed under hydrogen, the yield of 9 is increased to 42% and no 10 is formed. Compound 9 contains a cluster of eight rhodium atoms arranged in the form of a distorted cube. There are six μ4-GePh groups bridging each face of this distorted cube. Four of the rhodium atoms have two terminal carbonyl ligands, while the remaining four rhodium atoms have only one carbonyl ligand. Compound 10 contains a triangular cluster of three rhodium atoms with one terminal GePh3 ligand, three bridging GePh2 ligands, and one triply bridging GePh ligand. There is also one hydrido ligand that is believed to bridge one of the Rh−Ge bonds. Compound 9 reacted with PPhMe2 at 25 °C to give the tetraphosphine derivative Rh8(CO)8(PPhMe2)4(μ4-GePh)6, 11. The structure of 11 is similar to 9 e...

Disulfido metal carbonyl complexes containing manganese.

Abstract: An Account of recent studies of the chemistry of new disulfido metal carbonyl complexes containing manganese is presented. The coordination of the disulfido ligands, the nature of reactions at the manganese atom(s) and the nature of insertion reactions at the disulfido ligands are discussed.

Stable Hydrogen-Bonded Spherical Capsules Formed from Self-Assembly of Pyrogallol[4]arenes

Abstract: The self-assemblies of two pyrogallol[4]arenes held together by 48 intermolecular hydrogen bonds stably associate in the form of spherical hexameric capsules. The molecular structures of two hexameric capsules with large interior space were analyzed by single crystal X-ray crystallography.

Addition of Alkynes to High Nuclearity Platinum-Ruthenium Carbonyl Cluster Complexes*

Abstract: The reactions of the mixed metal cluster complexes PtRu5(CO)16(μ6-C)[Pt(PBu \(^{{\rm t}}_3\))], 5 and PtRu5(CO)16(μ6-C)[Pt(PBu \(^{\rm t}_{3})\)]2, 6 with selected alkynes have been investigated. Compound 5 adds one and two equivalents of PhC2H to yield the new compounds PtRu5(CO)15(μ6-C)(μ3-PhC2H)[Pt(PBu \(^{{\rm t}}_3\))], 8 and PtRu5(CO) \(_{13}(\mu_6\)-C)( \(\mu_3\)-PhC2H)2[Pt(PBu \(^{{\rm t}}_3\))], 9 at 40 and 68°C, respectively. Compound 6 was found to react with PhC2H at 40°C to yield the new compound PtRu5(CO) \(_{16}(\mu_{6}\)-C)( \(\mu_3\)-PhC2H)[Pt(PBu \(^{{\rm t}}_3\))]2, 10. The reaction of 6 with PhC2Ph at 97°C yielded the new compound PtRu5(CO) \(_{12}(\mu_{6}\)-C)( \(\mu_3\)-PhC2Ph)2[Pt(PBu \(^{{\rm t}}_{3}\))]2, 11. All products were characterized crystallographically by single crystal X-ray diffraction techniques. The structure of 8 consists of a pseudo-octahedral PtRu5 cluster with a second platinum atom bridging a basal edge of the Ru5 square pyramid. A triply bridging PhC2H ligand is bonded to the two platinum atoms and one of the ruthenium atoms. The structure of 9 consists of a nido-dodecahedral Pt2Ru5 cluster with a carbido ligand in the interior that is not bonded to all seven of the metal atoms. It also contains two triply bridging PhC2H ligands. The structure of 10 consists of a central octahedral cluster of five ruthenium atoms and one platinum atom. Two additional platinum atoms are bonded to the platinum atom in this cluster but these atoms are not bonded to any other metal atoms of the PtRu5 cluster. A triply bridging PhC2H ligand is coordinated to the group of three platinum atoms. The structure of 11 consists of an octahedral PtRu5 cluster with two additional platinum atoms capping two PtRu2 triangular faces. There are two PhC2Ph ligands bridging two Ru3 triangular faces of the central octahedron.

Trinuclear Metal Clusters with Three Different Metal Atoms from the Insertion of CpCo and Cp*Rh Groups into the S–S Bonds of [CpFeMn(CO)5(μ-S2)]2†

Abstract: Two cobalt containing products CpCoMn2(CO)6(μ3-S)2, 2 and Cp2FeCoMn(CO)3(μ3-S)2, 3 were obtained from the reaction of [CpFeMn(CO)5(μ-S2)]2, 1 with CpCo(CO)2 at room temperature. The two rhodium containing products: Cp*RhMn2(CO)6(μ3-S)2, 4 (11% yield) and CpFeCp*RhMn(CO)3(μ3-S)2, 5 (9% yield), were obtained from the reaction of 1 with Cp*Rh(CO)2. Compounds 3 and 5 were characterized structurally by single crystal X-ray diffraction methods. Compounds 3 and 5 both contain triangular clusters of three different types of metal atoms and have triply bridging sulfido ligands on each side of the cluster. A mechanism for their formation from 1 is proposed.

Disulfido Metal Carbonyl Complexes Containing Manganese

Abstract: An Account of recent studies of the chemistry of new disulfido metal carbonyl complexes containing manganese is presented. The coordination of the disulfido ligands, the nature of reactions at the manganese atom(s) and the nature of insertion reactions at the disulfido ligands are discussed.