Scott L. Ingham

Rigid rod σ-acetylide complexes of iron, ruthenium and osmium

Abstract The synthetic utility of bis(trimethylstannyl)alkynyls in the preparation of Group 8 metal (Fe 2+ , Ru 2+ , Os 2+ ) σ-acetylide monomeric, M(DEPE) 2 (CCC 6 H 5 ) 2 (M  Fe 2+ , Ru 2+ ; DEPE = 1,2-bis(diethylphosphino)ethane), Ru(DPPE) 2 (CCC 6 H 5 ) 2 (DPPE = 1,2-bis(diphenylphosphino)ethane), Os(DPPM) 2 (CCC 6 H 5 ) 2 (DPPM = 1,2-bis(diphenylphosphino)methane) and polymeric, [M(DEPE) 2 CCRCC] n (M  Fe 2+ , Ru 2+ ), [Os(DPPM) 2 CCRCC-] n (R = p -C 6 H 4 - C 6 H 4 - p , p -C 6 H 4 , p -C 6 H 2 (CH 3 ) 2 ) complexes is demonstrated. The linear arrangement of the acetylenic units around octahedral metal centres is confirmed by a single crystal X-ray structure determination of the model complex trans -[Ru(DPPE) 2 (CCC 6 H 5 ) 2 ].

Synthesis and characterisation of monomeric, dimeric and polymeric ferrocenylacetylides. Crystal structure of 1,1′-bis(phenylethynyl)ferrocene

Abstract The reactions of alkynyltrimethylstannanes with 1,1′-dilithioferrocene have given several ferrocenylacetylides, namely 1-pheny]-ethynyl-1′-iodo-ferrocene ( 1 ), 1,1′-bis(phenylethynyl)ferrocene ( 2 ), 1,4-di(1′-iodoferrocenylethynyl)benzene ( 3 ) and poly[1,4-(1′-ferrocenylethynyl)ethynylbenzene] ( 4 ). The versatility of this reaction for the formation of ferrocenylacetylides is demonstrated. The crystal structure of 2 has been determined, and shown to involve a linear array of the groups with a cis arrangement of the phenylethynyl ligands.

Ruthenium(II) σ-acetylide complexes; monomers, dimers and polymers

Abstract The complexes trans -[Ru(dppm) 2 (CCPh 2 ] and trans -[Ru(LL) 2 CCRCC] n − [LL = bis-diphenylphosphino)methane (dppm) or bis-(diphenylphosphino)ethane (dppe), R = p -C 6 H 4 or p -C 6 H 2 (CH 3 ) 2 ] have geen prepared by the reaction of the corresponding trans -[Ru(LL) 2 Cl 2 ] compound with Me 3 SnCCPh or Me 3 SnCCRCCSnMe 3 . Reactions between cis -[Ru(LL) 2 Cl 2 ], acetylenes and the salt NaPF 6 have yielded complexes of the type [CI(LL) 2 RuCCPhH] + PF 6 − . These were converted into the corresponding mono-acetylides, [Ru(LL) 2 Cl(CCPh)] by treatment with 1,8-diazabicyclo[5.4. Ojundec-7-ene(DBU) or alumina. Ale single crystal X-ray structure of [Ru(dppe) 2 Cl(CCPh)] confirms that during the reaction of the cis -dihalide species rearrangement takes place to give trans products.

Synthesis and electronic structure of rigid rod octahedral Ru-σ-acetylide complexes

Syntheses of the mono-, bis- and poly-nuclear Ru-σ-acetylide complexes, trans-[Ru(CO)2(PnBu3)2(CC C6H5)2], trans-[ClRu(CO)2(PnBu3)2CCpC6H4C6H4 pCCRu(CO)2(PnBu3)2Cl] and trans-[Ru(CO)2(PnBu3)2CC RCC]n(R = p-C6H4, p(CH3)2C6H2) are reported. A study of the electronic structure of model metal-acetylide complexes of Group 8, M(L)2,(L′)2(RH)2, ClRu(L or L′)4RRu(L or L′)4 Cl, [M(PH3)4(RH)]2R and [M(L)(L)2(R)]n, (M  Fe, Ru; L  L′ PH3, PMe3; L  CO, L′ PH3; R  CC, CCC6H4CC, CH CHpC6H4CHCH) has been carried out using the Fenske-Hall molecular orbital model. These results and a comparison of the IR (vCC stretching frequencies) and optical absorption (π-π★ energy band gap) spectra of these complexes provide evidence for the role of (i) auxiliary ligands, (ii) metal, and (iii) the bridging alkyne units in determining the extent of π-electron conjugation in the backbone of these rigid rod organometallic complexes.

Donor-acceptor-based vinylidene and σ-acetylide complexes of ruthenium and osmium

Abstract The synthesis of vinylidene, trans -[(dppm) 2 ClMCC(H)(R)]PF 6 , and σ-acetylide complexes, trans -[(dppm) 2 ClMCCR] (M = Ru , Os ; dppm = bis(diphenylphosphino)methane, Ph 2 PCH 2 PPh 2 ; R = p -C 6 H 5 , p -C 6 H 4 C 6 H 5 , p -C 6 H 4  2 , C 6 H 3 2-(CH 3 )-4-NO 2 , p -C 6 H 4 CH 3 ), and a single-crystal X-ray determination of trans -[(dppm) 2 ClRuCCC 6 H 4 - p -NO 2 ] are reported. The metal-phosphine fragment in these complexes acts as a donor and communicates with the para -substituted nitro acceptor group through the backbone. Such an interaction helps create a delocalized charge-transfer state from the donor to the acceptor.

Synthesis and structural characterisation of five-co-ordinate copper(I) and silver(I) 2,2′:6′,2″-terpyridine complexes

Five-co-ordinate copper(I) and silver(I) 2,2′ : 6′,2″-terpyridine (terpy) complexes of the type [M(PPh3)2(terpy)]ClO4(M = Cu or Ag) have been prepared by the reaction of terpy with either [Cu(PPh3)2(MeCN)2]ClO4 or [Ag(PPh3)2]ClO4. The complexes have been characterised by spectroscopic methods and single-crystal X-ray diffraction analysis. In the crystal the complexes consist of discrete monomers of distorted trigonal-bipyramidal geometry, with the metal atoms co-ordinated to the distal terpyridine pyridyl rings [Cu–N 2.386(3), 2.535(4); Ag–N 2.614(2), 2.561 (2)A] in axial sites. The co-ordination spheres are completed by the binding of the central pyridyl nitrogen atoms [Cu–N(2) 2.102(3), Ag–N(2) 2.457(2)A] and two PPh3 phosphorus atoms, which together define the equatorial planes. The 1H and {1H}-13C NMR spectra of [Cu(PPh3)2(terpy)]ClO4 and [Ag(PPh3)2(terpy)]ClO4 show that for each of the complexes the five-co-ordinate nature of the compounds is also retained in solution with the distal pyridyl rings being equivalent en the NMR time-scale.

Synthetic and structural characterisation of metal complexes of ferrocenylacetylene: novel donor–acceptor heterobimetallic materials

Two novel metal (ruthenium or osmium) complexes of ferrocenylacetylene have been synthesised and the crystal structure of [Fe(C5H5){C5H4CC[Os(dppm)2Cl]}][dppm = 1,2-bis(diphenylphosphino)-methane] has been determined; their solution redox chemistry indicated metal–metal interaction via the conjugated ligand group.

THE SYNTHESIS, STRUCTURE AND SELECTED REACTIVITY OF A SERIES OF TRICARBONYL RUTHENIUM COMPLEXES WITH 1,3-DIENES AND HETERODIENES

Abstract Displacement of the weakly ligated ethylene ligands in the complex Ru(CO) 3 { η 2 -C 2 H 4 } 2 has been used to synthesise a series of tricarbonyl ruthenium compounds of η 4 -coordinated 1,3-dienes and 1,3-heterodienes. Complexes of η 4 -coordinated 1,3-heterodienes could not be isolated due to their extreme reactivity. Selected reactions were performed to replace a carbonyl at the metal centre with a phosphite, or to modify the coordinated ligand by standard methodologies. Single crystal X-ray analyses have been performed on the complexes [Ru(CO) 3 {( E , E )-1,4-diphenylbuta-1,3-diene}], [Ru(CO) 3 {ethyl( E , E )-5-phenylpenta-2,4-dien-1-oate}], [Ru(CO) 3 {( E , E )-5-phenylpenta-2,4-dienal}] and [Ru(CO) 3 {( E , E )-5-phenylpenta-2,4-dienol}] and indicate a change in electronic environment within the diene moiety on coordination.

Synthesis and photochemical reactivity of phenylthioureatotriosmium cluster complexes: crystal structures of [Os3H(CO)10{µ-SC(NPh)(NHPh)}] and [Os3H(CO)9{µ3-SC(NPh)(NHPh)}]

The reaction of [Os3(CO)10(MeCN)2] with phenylthiourea (HL1) and N,N′-diphenylthiourea (HL2) yielded the thioureatotriosmium cluster complexes [Os3H(CO)10(µ-L)](L = L1 or L2) in which the thioureate moiety L bridges two osmium atoms via the sulfur atom. The complexes underwent photochemical reactions with a nitrogen atom of the thioureate ligand displacing a carbonyl on the third osmium atom to give [Os3H(CO)9(µ3-L)](L = L1 or L2). These reactions proceed cleanly and the quantum yields and apparent activation energies have been determined. The cluster complexes have been characterized by spectroscopic means and the structures of [Os3H(CO)10(µ-L2)] and [Os3H(CO)9(µ3-L2)] have been determined by X-ray diffraction: [Os3H(CO)10(µ-L2)], triclinic, space group P, a= 11.607(3), b= 14.341(3), c= 9.520(3)A, α= 104.92(2), β= 112.62(2), γ= 94.02(2)°, and Z= 2, [Os3H(CO)9(µ3-L2)], monoclinic, space group P21/m, a= 9.583(3), b= 14.249(3), c= 9.969(3)A, β= 103.53(2)°, and Z= 2. The structures were refined to R= 0.035 and 0.046 for 3791 and 3987 unique diffraction data respectively. In both clusters one edge of the osmium triangle is bridged by a sulfur atom and in [Os3H(CO)9(µ3-L2)] one of the nitrogen atoms of the thioureate ligand has displaced a carbonyl from the third osmium of the cluster.

Addition of some gold electrophiles to an octa-osmium carbonyl cluster: Thermodynamic vs. kinetic control

Abstract The reaction of the dianionic cluster [PPN] 2 [Os 8 (CO) 22 ] {[PPN] + =[N(PPh 3 ) 2 ] + } with Au 2 Cl 2 L {L=chelating phosphines bis -(diphenylphosphino)methane (dppm), 1,2- bis -(diphenylphosphino)ethane (dppe) or 1,4- bis -(diphenylphosphino)butane (dppb)} in the presence of an excess of the halide acceptor TlPF 6 , affords the neutral digold-substituted clusters [Os 8 (CO) 22 (Au 2 L)] {(1) L = dppm; ( 2 ) L = dppe; ( 3 ) L = dppb} in almost quantitative yield. The 31 P{1H} NMR spectra of these compounds indicate that the gold atoms are in non-equivalent environments and therefore cannot have a metal geometry similar to that previously reported for the related cluster [Os 8 (CO) 22 (AuPPh 3 ) 2 ]1 (4). A reinvestigation of the reaction between [PPN] 2 [Os 8 (CO) 22 ] and monogold fragment ‘AuPPh 3 + ’ has shown that, in addition to ( 4 ), a second isomer of Os 8 (CO) 22 (AuPPh 3 ) 2 ] ( 5 ) is formed, which on the basis of the spectroscopic data is thought to have the same metal geometry as compounds ( 1-3 ). A single crystal X-ray diffraction study of the compound [Os 8 (CO) 22 (Au 2 dppb)] ( 3 ) has shown that the metal core consists of a bicapped octahedron of osmium atoms, with one of the gold atoms capping the osmium octahedron, and the other gold atom bridging an edge of the osmium core.