Arthur J. Carty

Carbene complexes: XX. Electron-rich carbeneiron(0) trigonal bipyramidal carbonyls and their germanium(II) and tin(II) analogues [Fe(CO)3(L)(L′)] (L = CN(Me)(CH2)2NMe, L′ = PEt3, 3 CO's equatorial; or L = M(OAr)2 (equatorial: M = Ge OR Sn, Ar = C6H2But2-2,6-Me-4), L′ = CO)☆

Abstract The first bis(aryloxo)-main Group 14 metal(II)-transition-metal complexes eq -[Fe(CO) 4 ){M(OAr) 2 }] ( eq - denotes equatorial, Ar = C 6 H 2 Bu t 2 -2,6-Me-4, and M = Ge (II) or Sn (III)) have been prepared, from [Fe 2 (CO) 9 ] and the appropriate aryloxide M(OAr) 2 . X-ray structures of the complexes II and III show them to have the unusual (for a trigonal bipyramidal (tbp) [Fe(CO) 4 L] complex) eq -distorted tbp configuration. The related carbene complex [Fe(CO) 3 (L Me )(PEt 3 )] (I) [L Me = CN(Me)(CH 2 ) 2 N Me] has the tbp- rans -configuration in the crystal. The stereochemical integrity of each of I–III is maintained in solution. The exceptionally short Fe-Ge and Fe-Sn distances, and the relatively small deviation from coplanarity of the MO 2 plane and the Fe(CO) ax M planes are consistent with the ligands M(OAr) 2 being good π-acceptors but poor σ-donors in complexes II or III. By contrast, the X-ray data for complex I support the view the L Me is a strong σ-donor but weak π-acceptor. For a series of tbp- trans -[Fe(CO) 3 (L)(L′)] complexes, a comparison of Fe-C carb and Fe-P distances shows that the trans -influence of a ligand L falls in the sequence L = CO ρ PR 3 ρ L Me .

Coordination complexes of acetylenic phosphines and diphosphines : V. Acetylene bridged derivatives of dicobalt octacarbonyl

Abstract Reactions of the phosphinoacetylenes RR′PCCR″ (R  R′  Ph, R″  H, CF 3 , Ph, Me, t-Bu; R  R′  C 6 F 5 , R″  Ph, Me; R  Ph, R′  Me, R″  Me) with Co 2 (CO) 8 have been studied. Complexes of four types have been characterised: (A)(RR′PC 2 R″)CO 2 (CO) 6 (R  R′  C 6 F 5 , R″  Ph, Me; R  R′  Ph, R″  t-Bu), (B) (RR′PC 2 R″) 2 Co 4 (CO) 10 (R  R′  Ph, R″  H, CF 3 , Ph, Me; R  R′  C 6 F 5 , R″  Me; R  Ph, R′  Me, R″  Me), (C) (RR′PC 2 R″) 2 Co 2 (CO) 6 (R  R′  Ph, R″  t-Bu), (D) (RR′P(O)C 2 R″)Co 2 (CO) 6 (R  R′  Ph, R″  t-Bu; R  R′  C 6 F 5 , R  Ph). The complexes were characterised by microanalysis, IR, NMR and where possible mass spectra. Substitution reactions of the complexes with tertiary phosphites are described. In complexes of type (A) only the alkyne function is utilised whereas the tetranuclear compounds (B) have structures in which both alkyne and phosphorus moieties are coordinated. Compounds of type (C) are simple disubstituted phosphine complexes of Co 2 (CO) 8 and those of type (D) are μ-alkyne derivatives of acetylenic phosphine oxides. The mechanism of formation of complexes of type (B) is discussed in the light of IR data.

Open and closed ruthenium and osmium clusters with μ3-acetylide and phosphido bridges

Abstract The synthesis and structural characterisation of “open” M 3 (CO) 9 (CCR)(PPh 2 ) (M = Ru, Os; R = i-Pr, t-Bu) clusters with μ 3 -acetylides and phosphido groups bridging an “open” edge of the M 3 triangle are described. Facile conversion of Ru 3 (CO) 9 (CCR)(PPh 2 ) to “closed” Ru 3 (CO) 8 (CCR)(RPh 2 ) occurs via loss of CO and metal—metal bond formation, a process which is reversible under one atmosphere of CO.

Deposition of Ru and RuO2 thin films employing dicarbonyl bis-diketonate ruthenium complexes as CVD source reagents

Reaction of Ru3(CO)12 with 6 eq. of β-diketone ligands (hfac)H, (tmhd)H, (acac)H and (tfac)H at 160–170 °C in a hydrocarbon solvent (pentane or hexane) affords the diketonate complexes [Ru(CO)2(hfac)2] (1), [Ru(CO)2(tmhd)2] (2), [Ru(CO)2(acac)2] (3) and [Ru(CO)2(tfac)2] (4) in high yields. These ruthenium complexes were characterized by spectroscopic methods; a single crystal X-ray diffraction study was carried out on one isomer of the tfac complex (4a), revealing an octahedral coordination geometry with two CO ligands located at cis-positions and with the CF3 groups of the β-diketonate ligands trans to the CO ligands. Thermogravimetric analysis of complex (1) showed an enhanced volatility compared to the parent acac complex (3), attributed to the CF3 group reducing intermolecular attraction. Employing complexes (1) and (2) as CVD source reagents, ruthenium thin films can be deposited at temperatures of 350 °C–450 °C under an H2 atmosphere or at temperatures of 275 °C–400 °C using a 2% mixture of O2 in argon as carrier gas. For deposition carried out using complex (1) and under 100% O2 atmosphere, RuO2 thin films with a preferred (200) orientation were obtained. The as-deposited thin films were characterized by surface and physical analytical techniques, such as scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction analysis (XRD) and four-point probe measurement.

Platinum cluster compounds: X-ray structures of phosphido-bridged bi- and tri-nuclear complexes with strong metal–metal bonds derived from [Pt(PPh3)4]

Binuclear [(Pt2(PPh3)2(PPh2)2] and trinuclear [Pt3(PPh3)2(PPh2)3Ph] cluster compounds of platinum have been prepared from [Pt(Ph3P)4] and characterised by X-ray crystal structure analyses of their benzene solvates.

Carbon-13 NMR shifts of bridging acetylides in polynuclear complexes

Abstract Carbon-13 NMR data for a range of iron group polynuclear acetylide complexes with μ 2 -η 2 , μ 3 -η 2 and μ 4 -η 2 alkynyl groups are presented. For doubly bridging μ 2 -η 2 -acetylides of Fe, Ru and Os, the C α resonance lies in the range 65–110 ppm downfield of TMS, while C β shifts cover the range 90–110 ppm. In μ 3 -η 2 -complexes C α lies in the region 115–220 ppm and is always downfield of C β (43–153 ppm). For μ 4 -η 2 -acetylides, C α , is also downfield of C β with values lying in the ranges 185–230 and 91–165 ppm, respectively. Comments on the most appropriate experimental parameters for the observation of 13 C spectra of acetylides and techniques for assigning resonances are included.

Fluorinated aminoalkoxide CuII complexes: new CVD precursors for deposition of copper metal

Volatile low-melting CuII metal complexes of formula Cu[OC(CF3)R1CH2NHR2]2 (R1 = CF3 or CH3; R2 = CH2CH2OMe, Bui, or But) and Cu[OC(CF3)R1CH2NMe2]2 (R1 = CF3 or CH3) have been synthesized and characterized by spectroscopic methods. A single-crystal X-ray diffraction study on Cu[OC(CF3)2CH2NHCH2CH2OMe]2 shows that one methoxyethyl group of the aminoalkoxide ligand forms an intramolecular dative bond to the Cu atom to produce a square-pyramidal geometry at the metal center, while the second is linked to the Cu atom of the adjacent molecule, giving an N2O4 octahedral coordination arrangement. For the second Bui-substituted complex, Cu[OC(CF3)2CH2NHBui]2, the X-ray structural analysis demonstrated an N2O2 square-planar geometry, with one alkoxide oxygen atom forming strong H-bonding to an adjacent water molecule. Metal CVD experiments were carried out, showing that the source reagents Cu[OC(CF3)2CH2NHBui]2, Cu[OC(CF3)2CH2NHBut]2, and Cu[OCMe(CF3)CH2NHBui]2, which possess a secondary amino group, are capable of depositing copper metal at temperatures of 250–300 °C under inert Ar carrier gas, while Cu[OCMe(CF3)CH2NMe2]2, with a tertiary amine group, requires the use of reductive H2 carrier gas to induce metal deposition at lower temperatures.

The Interaction of Organomercury Pollutants with Biologically Important Sites: An X-ray study of the 2:1 Complex between Methylmercury and Penicillamine

The toxic pollutant methylmercurychloride forms 1:1 and 2:1 complexes with the sulfur amino acid DL-penicillamine. The mode of binding of the methylmercury by penicillamine has been established by a three-dimensional X-ray study of [CH3Hg]2(SC(CH3)2CHNH2COO).

Terminal chloroaminophosphido and aminophosphinidene complexes of molybdenum

Abstract The phosphido complex [Cp*Mo(CO) 3 P(Cl)N i Pr 2 ] ( 1 , Cp*=C 5 (CH 3 ) 5 ) was formed by the reaction of Li[Cp*Mo(CO) 3 ] with i Pr 2 NPCl 2 . Chloride abstraction from 1 leads to the aminophosphinidene complex [Cp*(CO) 3 MoPN i Pr 2 ][AlCl 4 ] ( 2 ) which reacts with phenylacetylene to form the metalaphosphacyclobutene complex [Cp*(CO) 3 Mo{P(N i Pr 2 )C(Ph)C H}][AlCl 4 ] ( 3 ).

Synthesis and structure of metallocarbon clusters bearing pendant ethynyl ligands. X-ray crystal structures of Os3(CO)9(μ-CO)(μ3-η1,η1,η2-Me3SiCCC2CCSiMe3), Os3Ru(CO)12(μ4-η1,η2,η1,η2-Me3SiCCC2CCSiMe3), Ru4(CO)12(μ4-η1,η2,η1,η2-Me3SiCCC2CCSiMe3) and {Ru4(CO)12}{Co2(CO)6}(μ4-η1,η2,η1,η2:μ-η2,η2-Me3SiC2CCC2SiMe3)

Abstract The reaction of 1,6-bis(trimethylsilyl)hexa-1,3,5-triyne (1) with Os3(CO)10(NCMe)2 yields Os3(CO)9(μ-CO)(μ3-η1,η1,η2-Me3SiCCC2CCSiMe3) (2), which on treatment with Ru3(CO)12 gives Os3Ru(CO)12(μ4-η1,η2,η1,η2-Me3SiCCC2CCSiMe3) (3). In the case of the reaction between 1 and Ru3(CO)12 the major products are the butterfly cluster Ru4(CO)12(μ4-η1,η2,η1,η2-Me3SiCCC2CCSiMe3) (4) and the ruthenole complex Ru2(CO)6{μ-η2,η5-C(CCSiMe3)C(CCSiMe3)C(CCSiMe3)C(CCSiMe3)} (5). Cluster 4 reacts with Co2(CO)8 to give {Ru4(CO)12}{Co2(CO)6}(μ4-η1,η2,η1,η2:μ-η2,η2-Me3SiC2CCC2SiMe3) (6) in which the butterfly cluster core has slipped along the hexatriyne chain.