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Enhanced blood vessel (BV) formation is thought to drive tumor growth through elevated nutrient delivery. However, this observation has overlooked potential roles for mural cells in directly affecting tumor growth independent of BV function. Here we provide clinical data correlating high percentages of mural-β3-integrin-negative tumor BVs with increased tumor sizes but no effect on BV numbers. Mural-β3-integrin loss also enhances tumor growth in implanted and autochthonous mouse tumor models with no detectable effects on BV numbers or function. At a molecular level, mural-cell β3-integrin loss enhances signaling via FAK-p-HGFR-p-Akt-p-p65, driving CXCL1, CCL2, and TIMP-1 production. In particular, mural-cell-derived CCL2 stimulates tumor cell MEK1-ERK1/2-ROCK2-dependent signaling and enhances tumor cell survival and tumor growth. Overall, our data indicate that mural cells can control tumor growth via paracrine signals regulated by β3-integrin, providing a previously unrecognized mechanism of cancer growth control.

Integrins are a family of cell-extracellular matrix adhesion molecules that play important roles in tumor angiogenesis. αvβ3-Integrin has received much attention as a potential anti-angiogenic target because it is upregulated in tumor-associated blood vessels. Agents targeting αvβ3-integrin are now showing some success in phase III clinical trails for the treatment of glioblastoma, but the exact function of this integrin in tumor angiogenesis is still relatively unknown. This review highlights some of the recent data illustrating that β3-integrins play both pro-angiogenic and anti-angiogenic roles in tumor angiogenesis depending on the context. Specifically we will discuss how the following differentially influence β3-integrin's role in tumor angiogenesis: first, cell-matrix interactions, second, β3-integrin inhibitor doses, third, cell type, and fourth, other interacting molecules.

Integrin alpha3beta1 is a major receptor for laminin. The expression levels of laminins-8 and -10 in the basement membrane surrounding blood vessels are known to change during tumor angiogenesis. Although some studies have suggested that certain ligands of alpha3beta1 can affect angiogenesis either positively or negatively, either a direct in vivo role for alpha3beta1 in this process or its mechanism of action in endothelial cells during angiogenesis is still unknown. Because the global genetic ablation of alpha3-integrin results in an early lethal phenotype, we have generated conditional-knockout mice where alpha3 is deleted specifically in endothelial cells (ec-alpha3-/-). Here we show that ec-alpha3-/- mice are viable, fertile, and display enhanced tumor growth, elevated tumor angiogenesis, augmented hypoxia-induced retinal angiogenesis, and increased vascular endothelial growth factor (VEGF)-mediated neovascularization ex vivo and in vivo. Furthermore, our data provide a novel method by which an integrin may regulate angiogenesis. We show that alpha3beta1 is a positive regulator of endothelial-VEGF and that, surprisingly, the VEGF produced by endothelial cells can actually repress VEGF-receptor 2 (Flk-1) expression. These data, therefore, identify directly that endothelial alpha3beta1 negatively regulates pathological angiogenesis and implicate an unexpected role for low levels of endothelial-VEGF as an activator of neovascularization.

The nickel and platinum complexes [MX2(dppe)] (X=Cl, Br) react with bi- and tri-valent metal diethyldithiocarbamates [M′(S2CNEt2)n] (M′=Pb, Zn, Cd, Hg, Ni, MoO2, VO, n=2; M′=Co, Fe, Mn, n=3) to afford salts [M(S2CNEt2)(dppe)]2[M′X4]; reactions involving [Cu(S2CNEt2)2] and [Ag(S2CNEt2)] gave salts of the form [M(S2CNEt2)(dppe)][M′X2] (M′=Cu, Ag). The complexes cis [RuCl2(dppm)2], [CoCl2(dppe)] and [PdX2(bipy)] likewise react with the same dithiocarbamates to form salts [Ru(S2CNEt2)(dppe)2]2[M′Cl4] [Co(S2CNEt2)2(dppe)]2[M′Cl4] and [Pd(S2CNnBu2)(bipy)]2[M′X4], respectively. Sample reactions involving other S-chelate ligands—S2COEt−, S2PPh2 − and S2P(OEt)2 −—appear to follow the same general pattern. However, the O-ethyldithio carbonates (ethylxanthates) are partly converted to the corresponding dithiocarbonates. An anomalous reaction between [CoCl2(dppe)] and [Zn(S2CNEt2)2] in the presence of (S2CNEt2)2 affords the novel complex [Co(S2CNEt2)2(dppe)]2[Cl3ZnO:(Ph)2PCH2CH2P(Ph)2:OZnCl3]. A selection of these salts have been fully characterised by elemental analysis and spectroscopic techniques, the remainder have been identified by spectroscopic methods alone. X-ray crystal structures are reported for the salts [Ni(S2CNEt2)(dppe)]2 [HgBr4], [Pt(S2CNEt2)(dppe)]2[CdCl4], [Co(S2CNEt2)2(dppe)]2[Cl3ZnO:(Ph)2PCH2CH2P(Ph)2:OZnCl3] and [Pd(S2CNnBu2) (bipy)]2[CdCl4].

N,N′-Diphenylamidines, PhNC(R)NHPh (R=H, Me, Et, Ph), and 1,3-diaryltriazenes, ArNNNHAr (Ar=p-C6H4X, X=H, Cl, Me, OMe) react with ruthenium(II) complexes, [RuCl2(C7H8)]n, [RuCl2(CO)2]n and [RuCl2(Me2SO)4] in the presence of a base (NEt3 or Na2CO3) to afford a selection of bis(chelate) products [Ru{PhNC(R)NPh}2L2] and [Ru(ArNNNAr)2L2] (L=CO, Me2SO; L2=C7H8). In contrast one particular combination — [RuCl2(Me2SO)4]/PhNC(H)NHPh/NEt3 — in refluxing dimethylformamide yields a novel amidine fragmentation product [RuCl(NH2Ph){PhNC(H)NPh}(Me2SO)2] which has been characterised by X-ray diffraction methods.

N,N′-Diphenylthiourea reacts with [RuHCl(CO)(PPh3)3] and [Ru(H)2(CO)(PPh3)3] in refluxing benzene to afford the N,N′-diphenylthioureido complexes [RuCl{PhNC(NHPh)S}(CO)(PPh3)2] and [RuH{PhNC(NHPh)S}(CO)(PPh3)2], respectively. Under more forcing conditions in refluxing toluene the precursors [MHCl(CO)(PPh3)3] (M=Ru or Os) and [Os(H)2(CO)(PPh3)3] afford the thioureido complexes [M{PhNC(NHPh)S}2(CO)(PPh3)] and the known N-phenylthioformamidato complex [OsH{PhNC(H)S}(CO)(PPh3)2], respectively. The reaction of [RuCl2(PPh3)3] with N,N′-diphenylthiourea and triethylamine in boiling toluene yields [Ru{PhNC(NHPh)S}2(PPh3)2]. Finally the reaction of mer-[Ir(H)3(PPh3)3] with N,N′-diphenylthiourea in boiling toluene affords [Ir(H)2{PhNC(NHPh)S}(PPh3)2]. Spectroscopic evidence indicates that the N,N′-diphenylthioureido anions are bound as N,S chelates, and this coordination mode has been confirmed for [Ru{PhNC(NHPh)S}2(CO)(PPh3)] by an X-ray crystal structure determination. Trends in exocyclic CNR2 bond lengths for related guanidinato, thioureido and dithiocarbamato complexes are reported.

Reactions of [RuCl 2 (Me 2 SO) 4 ] with silver carboxylates, [Ag(O 2 CR)] (R=Me, CF 3 ) in cold dichloromethane afford the title compounds, [Ru(O 2 CR) 2 (H 2 O)(Me 2 SO) 3 ] in good yield as pale cream crystals. X-ray crystal structure determinations have been performed on both complexes. In each case the geometry about the ruthenium centre is essentially octahedral with three S-bonded Me 2 SO ligands arranged in a fac configuration, two monodentate carboxylate anions and a coordinated H 2 O molecule. The carboxylate ligands are H-bonded to the H 2 O ligand via their non-coordinated oxygen atoms. The structures are compared with those previously reported for the alcohol dehydrogenation catalyst [Ru(O 2 CCF 3 ) 2 (MeOH)(CO)(PPh 3 ) 2 ] and a closely related ruthenium carboxylate complex [Ru(O 2 CCF 3 ) 2 (H 2 O)(PMe 3 ) 3 ].

The palladium complexes [PdCl2{Ph2P(CH2)nPPh2}] (n=1, 3, 4) react with the bi- and tri-valent metal diethyldithiocarbamates [M(S2CNEt2)2] (M=Zn, Cd, Hg, Pb) and [Mn(S2CNEt2)3] in cold dichloromethane solution to afford salts of the general form [Pd(S2CNEt2){Ph2P(CH2)nPPh2}]2[MCl4] in almost quantitative yield. X-ray crystal structures are reported for the salts [Pd(S2CNEt2){Ph2P(CH2)nPPh2}]2[MCl4] (n=1, 4; M=Cd: n=3, M=Hg). Structural parameters, IR and NMR spectroscopic data for these salts are compared with similar data previously reported for salts of the related cation [Pd(S2CNEt2){Ph2P(CH2)2PPh2}]+.

N,N′,N″-Triphenylguanidine (TpgH) reacts with [Ru(H)2(CO)(PPh3)3] in refluxing toluene and with [Os(H)2(CO)(PPh3)3] in refluxing o-xylene to yield the guanidinate(−1) complexes [RuH(Tpg)(CO)(PPh3)2] (1) and [Os(Tpg)2(CO)(PPh3)] (2), respectively. The reaction of TpgH with [RuCl2(PPh3)3] in refluxing toluene affords a new route to the known complex [Ru(Tpg)2(CO)(PPh3)] (3). Finally the reaction of mer-[Ir(H)3(PPh3)3] with TpgH in refluxing toluene yields the iridium(III) dihydride complex [Ir(H)2(Tpg)(PPh3)2] (4). X-ray crystal structure determinations are reported for (1) and (4).

The palladium complex [PdCl2(PhCN)2] reacts readily with metal bis(dialkyl dithiocarbamates) [M(S2CNR2)2] (M = Pb, Zn, Cd, Hg, Cu, Ni, MoO2, VO; R = Et, Bun), in refluxing dicloromethane, to afford the known complexes [|PdCl(S2CNR2)|2] in virtually quantitative yield. In boiling acetonitrile the diphosphine complexes [PdX2(Ph2PCH2CH2PPh2)] (X = Cl, Br) react readily with bi- and trivalent metal diethyl dithiocarbamates [M(S2CNEt2)n] (M = Pb, Zn, Cd, Hg. Ni, MoO2, VO n = 2; M = Co, Fe, Mn, n = 3) to afford salts of the general form [Pd(S2CNEt2)(Ph2PCH2CH2PPh2)]2+[MX4]2−. Diethyl dithiocarbamates of copper(II) and silver(I) form salts of the [Pd(S2CNEt2)(Ph2PCH2CH2PPh2)]+ cation containing linear [CuX2]− and [AgX2]− anions respectively (X = Cl, Br). The X-ray crystal structures of [Pd(S2CNEt2)(Ph2PCH2CH2PPH2)][CuCl2] and [Pd(S2PCH2CH2PPh2][AgCl2] · 0.5CH2Cl2 are reported.

Some dithiocarbamato-bridged heterobimetallic complexes [M′{M(S 2 CNR 2 ) 3 } 2 ] and [{M′M(S 2 CNR 2 ) 4 } n ], obtained by successive addition of stoichiometric amounts of bivalent metal salts MX 2 (M = Zn, Cd or Hg) and M′Y 2 (M′ = VO, Mn, Fe, Co, Ni, Cu or Zn) to a solution of a sodium dithiocarbamate, are reformulated as mixtures of homonuclear complexes involving, in some instances (M′ = Mn, Fe or Co), trivalent [M′(S 2 CNR 2 ) 3 ] species.

A decision support system (DSS) was developed in consultation with wheat farmers in the mediterranean wheat growing region of Western Australia. This system is targeted at decisions to be made at the start of the season and provides information about changes in the yield distribution of wheat given seasonal conditions to date. The DSS also access to historical weather records, which may be analysed according to simple, user defined rules.

Awassi sheep are large framed, fat tailed sheep mostly grown and consumed in Middle East countries. To provide an opportunity for Australian farmers to sell these sheep to Middle East countries, in 1983 an Awassi fat tail sheep importation program was initiated. This program has enabled many Awassi sheep to be raised in quarantine in Western Australia. For the first time Australian farmers now have an opportunity to produce Awassi sheep. To help administrators and farmers determine the likely place and profitability of these Awassi sheep in the farming systems of Western Australia, farming system models were employed. Models of the dryland farming systems in three regions of Western Australia were augmented with Awassi sheep production options. Modelling results suggest that only modest price premiums for Awassi cross sheep are sufficient to ensure the Awassi sheep enterprise is a profitable inclusion in the farming systems of the southern and western wheatbelt regions of Western Australia, providing particular Awassi flock options are adopted.

The ruthenium(I) amidinato complex [Ru{PhNC(Me)NPh}(CO)3]2 has been prepared by heating [Ru3(CO)12] with the free amidine, PhNC(Me)NHPh, in boiling benzene under a carbon monoxide atmosphere, and by heating [{Ru(O2CMe)(CO)2}2]n with free amidine and triethylamine in acetonitrile under carbon monoxide. The structure of [Ru{PhNC(Me)NPh}(CO)3]2 has been determined by X-ray diffraction methods. The binuclear complex has two Ru(CO)3 units linked by an RuRu bond [2.714(1) A] and a cis pair of bridging amidinato ligands. Variable temperature 1H and 13C {1H} NMR spectra show evidence of hindered rotation about the Nphenyl bonds of the amidinate ligands. An attempt to prepare the corresponding propionamidinate derivative gave a product which is tentatively formulated as [Ru{PhNC(Et)NPh}(CO)2(HO2CMe)]2 on the basis of analytical and spectroscopic evidence.

Homoleptic tris(triazenido) derivatives of ruthenium, osmium, rhodium and iridium, M(ArNNNAr) 3 (Ar = p -C 6 H 4 X; X = H, Me or Cl), have been prepared by treatment of the chlorides or chloro complexes—RuCl 3 (aq.), (NH 4 ) 2 OsCl 6 (aq.), RhCl 3 (aq.) and (NH 4 ) 2 IrCl 6 (aq.), respectively—with excess 1,3-diaryltriazene and triethylamine in boiling ethanol (M = Ru, Rh) or aqueous ethanol (M = Os, Ir). The sparingly soluble, air-stable, deep green (M = Ru, Os) or red-orange (M = Rh, Ir) complexes have been characterized by vibrational and NMR spectroscopy, and by magnetic measurements.

The synthesis and X-ray crystal structures of the acetamidinato complexes (M = Ru, Rh) and the triazenido complexes and are reported.

Mononuclear rhodium(II) dithiocarbamato complexes ‘Rh(S 2 CNR 2 ) 2 (PPh 3 )’ and ‘Rh(S 2 CNR 2 ) 2 ’, (R=Me, Et) have been shown to be mixtures of various rhodium(III) dithiocarbamato complexes.

Platinum metal hydrido and trifluoroacetato complexes react with N,N′-diphenylamidines, PhNC(R)NHPh (R = H, Me, Et, Ph), giving the amidinato derivatives Ru{PhNC(R)NPh}2(CO)(PPh3), MX{PhNC(R)NPh}(CO)(PPh3)2 and IrX2{PhNC(R)NPh}(PPh3)2 (M = Ru, Os; X = H, Cl; X2 = H2, Cl2 or HCl). The reactions of RuH2(PPh3)4 and OsH4(PPh3)3 with amidines are accompanied by an avid alcohol decarbonylation reaction to form the carbonyls MH{PhNC(R)NPh}(CO)(PPh3)2.

The complexes (MH(O2CCF3) (CO) (PPh3)2] and (M(O2CCF3)2(CO)(PPh3)2] (M = Ru or Os) react with terminal and internal acetylenes to afford oligomerisation and hydrogenation products, respectively, together with vinylic complexes, including the ruthenium species [Ru(C4HPh2)(O2CCF3)(CO) (PPh3)2], which has been shown by x-ray diffraction methods to contain a 1,4-diphenylbut-1-en-3-yn-2-yl ligand.

Ligand exchange reactions performed in polar solvents afford a convenient general route to an extensive series of cationic trimethyl and triethul phosphite derivatives of gold, silver and the platinum metals, which were islated as theri tetraphenylborate salts. The products, which were characterised by elemental analysis, proton n.m.r. spectroscopy and conductivity measurements, contain cations of the general formulae {M[P(OR)3]6}2+ (M = Ru, Os);{MX[P(OR)3]5}+ (M = Ru, X = H, Cl, Br, M = Os, X = Br);{M[P(OR)3]5}+ (M = Rh, Ir); {M[p(OR)3]4}2+ and{MCl[P(OR)3]3}+ (M = Pd, Pt) and {M[p(OR)3]4}+ (M = Ag, Au) (R = Me or Et throughout). A qualitative description of the coupling patterns observed in the proton n.m.r. spectra of these cations is given, and is interpreted in terms of ligand rearrangement, exchange and dissociation processes.

The hydrides [MH(O2CCF3)(CO)(PPh3)2] (M = Ru or Os) react with disubstituted acetylenes PhCCPh and PhCCMe to afford vinylic products [M{C(Ph)CHPh}(O2CCF3)(CO)(PPh3)2] and [M{C(Ph)CHMe}(O2CCF3)(CO) (PPh3)2]/[M{C(Me)CHPh}(O2CCF3)(CO)(PPh3)2] respectively. Acidolysis of these products with trifluoroacetic acid in cold ethanol liberates cis-stilbene and cis-PhHCCHMe respectively thus establishing the cis-stereochemistry of the vinylic ligands. The complexes [M(O2CCF3)2(CO)(PPh3)2] formed during the acidolysis step undergo facile alcoholysis followed by β-elimination of aldehyde to regenerate the parent hydrides [MH(O2CCF3)(CO)(PPh3)2] and thereby complete a catalytic cycle for the transfer hydrogenation of acetylenes. The molecular structure of the methanol-adduct intermediate, [Ru(O2CCF3)2(MeOH)(CO)(PPh3)2] has been determined by X-ray methods and shows that the coordinated methanol is involved in H-bonding with the monodentate trifluoroacetate ligand [MEO-H---OC(O)CF3; O...O = 2.54 A]. The hydrides [MH(O2CCF3)(CO) (PPh3)2]react with 1,4-diphenylbutadiyne to afford the complexes [M{C(CCPh)CHPh} (O2CCF3)(CO)(PPh3)2]. The ruthenium product, which has also been obtained by treatment of [RuH(O2CCF3)(CO)(PPh3)2] with phenylacetylene, has been shown by X-ray diffraction methods to contain a 1,4-diphenylbut-1-en-3-yn-2-yl ligand. The osmium complexes [Os(O2CCF3)2(CO)(PPh3)2], [OsH(O2CCF3)(CO)(PPh3)2] and [Os{C(CCPh)CHPh}(O2CCF3)(CO)(PPh3)2] all serve as catalysts for the oligomerisation of phenylacetylene. Acetylene reacts with [Ru(O2CCF3)2(CO)(PPh3)2] in ethanol to afford the vinyl complex [Ru(CHCH2)(O2CCF3)(CO)(PPh3)2].

The ruthenium(I) triazenido complexes [Ru(ArNNNAr)(C0)3]2 (Ar = p-C6H4Me or p-C6H4Cl) have been prepared by heating RU3(CO)12 with free triazene in benzene under a carbon monoxide atmosphere, and by heating [Ru(O2CMe)(CO)2]n with free triazene and triethylamine in acetonitrile under carbon monoxide. Reactions of the diruthenium(I/I) triazenido complexes with PPh3, P(OME)3 or ArNNNHAr (Ar =p-C6H4Cl) afford axial substitution products of the general form [Ru(ArNNNAr)(CO)2L]2. However, with ArNNNHAr (Ar = p-C6H4Me) cleavage of triazene to generate axial p-toluidine ligands occurs. The structure of the p-toluidine adduct, [Ru(ArNNNAr)(CO)2(NH2Ar)]2 has been determined by X-ray diffraction methods. The compound crystallizes in space group P 1 with a = 11.350(1), b = 20.582(4), c= 10.371(5) A, α = 100.75(4), β = 104.30(3), γ = 84.40(1)°; U = 2303.89 A3 and Z = 2.

The complexes [MCl2(CO)(AsPh3)3] (M = Ru or Os) have been prepared by addtition of EuCl3· 3H2O or Na2OsCl6· 6H2O and aqueous formaldehyde to excess triphenylarsine in boiling 2-methoxyethanol. Similar reaction, modified by addition of triethylamine, afford the corresponding hydrides [MHCl(CO)(AsPh3)3]. In boiling toluene the complexes [MCl2(CO)(AsPh3)3] readily eliminate triphenylarsine to form binuclear complexes [M2Cl4(CO)2(AsPh3)4]. Carbonylation of the complexes [MCl2(CO)(AsPh3)3] and [MHCl(CO)(AsPh3)3] in boiling benzene affords the dicarbonyls [MCl2(CO)2(AsPh32] and [MHCl(CO)2(AsPh3)2] respectively. Reduction of the complexes [MCl2(CO)(AsPh3)3] with sodium borohydride in ethanol yields the corresponding dihydrides [MH2(CO)(AsPh3)3]. The tetrahydride [OsH4(AsPh3)3] is readily prepared from Na2OsCl6· 6H2O, triphenylarsine and sodium borohydride in ethanol, the facial isomer of [IeH3(AsPh3)3] is similarly obtained from Na2IrCl6· 6H2O. By careful adjustment of pH and chloride ion concentration the reaction of Na2IrCl6· 6H2O with triphenylarsine in boiling 2-methoxyethanol can be made to yield [IrH2Cl(AsPh3)3], [IrHCl2(AsPh3)3] or [IrCl3(AsPh3)3]. Attempts to prepare a range of other platinum metal triphenylarsine complexes are described. The new complexes have been characterised by elemental analysis, melting point and spectroscopic data.

The complex “Cu(SO4)(btaH)4·2H2O” (btaH = benzotriazole) deposited as deep blue crystals from aqueous CuSO4·5H2OH2SO4btaH solutions been shown by X-ray diffraction methods to be a monohydrate [Cu(SO4)(H2O)(btaH)3·btaH]. The crystals contain five-coordinate, tetragonal pyramidal Cu(SO4)(H2O)(btaH)3 units and bridging btaH molecules linked together by a three-dimensional array of H-bonding interactions.

p-Tolyl iso cyanate (RNCO) undergoes coordination and fragmentation reactions with [MHX(CO) (PPh3)3] (M = Ru or Os; X = Cl or Br), [MH2(CO)(PPh3)3] and [RuH2(PPh3)4] or [OSH4(PPh3)3] to yield products containing formamido , ureylene [RNC(O)NR] and formamidinato ligands respectively.

The complexes [MHCl(CO)(PPh3)3] (M = Ru or Os) readily undergo substitution at the site trans to the hydride ligand to afford phosphinite-, phosphonite-, or phosphite-containing products [MHCI(CO)(PPh3)2L] [L = P(OR)Ph2, P(OR)2Ph or P(OR)3 respectively; R = Me or Et]. The ruthenium complexes alone undergo further substitution to afford complex cations [RuH(CO)(PPh3)nL4−n]+ [n = 2, L = P(OMe)3; n = 1, L = P(OR)3; n = 0, L = P(OR)2Ph or P(OR)Ph2] which were isolated and characterised as their tetraphenylborate salts. Synthesis of the cationic complexes [IrHL5][BPh4]2 [L = P(OR)3, R = Me or Et] is also reported. Stereochemical assignments based on NMR data are given, and second order 31P and high field 1H NMR patterns are analysed.

The precursors MH 2 (CO)(PPh 3 ) 3 (M = Ru or Os), Ru(CO) 3 (PPh 3 ) 2 /OsH 2 (CO) 2 (PPh 3 ) 2 and IrH(CO)(PPh 3 ) 3 react with 1,3,4-thiadiazole-2,5-dithiol (tddtH 2 ) in boilig toluene to afford the 1,3,4-thiadiazole-2,5-dithiolato (tddtH) complexes M(tddtH) 2 (CO)(PPh 3 ) 2 , M(tddtH) 2 (CO) 2 (PPh 3 ) 2 and IrH(tddtH) 2 (CO)(PPh 3 ) 2 respectively. The molecular structure of the ruthenium complex Ru(tddtH) 2 (CO)(PPh 3 ) 2 has been determined by X-ray diffraction methods, the crystals are triclinic space group P 1 , Z = 2, unit cell dimensions are a = 13.051(3), b = 16.404(7), c = 16.500(5) A, α = 119.60(2), β = 91.46(2), γ = 104.21(3)°, ( V = 2932.0(16) A 3 . The structure contains octahedral ruthenium(II) with mon-dentate (S-coordinated) and bi-dentate (N,S-coordinated) tddtH ligands, a carbonyl group and a trans pair of triphenylphosphine ligands. The complexes M(tddtH) 2 (CO)(PPh 3 ) 2 and the closely related ruthenium 5-methyl-1,3,4-thiadiazole 2-thiolato complex Ru(mtdt) 2 (CO)(PPh 3 ) 2 have been shown by 1 H NMR to display dynamic interchange of mono- and bi-dentate thiolate ligands. Some rhodium(I), palladium(0) and platinum(0) complexes of tddtH 2 are tentatively reformulated.

1,3-Diaryltriazenes, ArN = NNHAr (Ar = Ph, p-MeC6H4 and p-MeOC6H4) react with platinum metal halide complexes in the presence of triethylamine to afford products containing mono- or bi-dentate (chelate or bridging) 1,3-diaryltriazenide ligands. Complexes prepared in this manner include derivatives of ruthenium(II), 2(PPh3)2] and (CO)(PPh3)2]; rhodium(I), 2], (C8H12)(PPh3)] and (CO)(PPh3)2]; palladium(II) L2] (X = Cl, L = PPh3, PEt3, AsPh3, PMePh2; X = Br, L = PMePh2; X = I, L = PMe2Ph), and 2(PMe2Ph)2]; and platinum(II(, [PtCl L2] (L = PPh3, PEt3, and PEt2Ph; L = C8H12). The intramolecular N(1)–N(3) exchange process: displayed by the monodentate 1,3-diaryltriazenido derivatives of rhodium(I), palladium(II) and platinum(II) have been studied by dynamic proton NMR spectroscopy, and thermodynamic parameters of activation have been determined. ΔH≠ values were found to lie within the range ca. 32–44 kJ mol−1 for the palladium(II) and platinum(II) complexes, ΔS≠ values are all negative.

The ruthenium(II) and osmium(II) complexes MCl 2 (PPh 3 ) 3 , undergo oxidative substitution reactions with β-diketones under aerobic conditions in warm benzene to afford ruthenium(III) and osmium(III) β-diketonate complexes, MCl 2 (β-diketonate)(PPh 3 ) 2 . Generally these products appear to adopt the less sterically hindered trans -phosphine stereochemistry, but one example, RuCl 2 {CF 3 C(O)CHC(O)CF 3 }(PPh 3 ) 2 , deposits from hot and cold reactions as yellow ( trans -phosphines) and red ( cis -phosphines) isomers, respectively.

Reactions of 4,6-dimethylpyrimidine-2-thiol (Me 2 pymSH) and its oxidation product bis(4,6-dimethylpyrimidine-2-yl)disulphide (Me 2 pymSSpymMe 2 ) with a range of platinum metal complexes are described. The chlorohydrides [MHCl(CO)(PPh 3 ) 3 ] (M=Ru, Os) react with Me 2 pymSH in refluxing toluene to afford [RuCl(Me 2 pymS)(CO)(PPh 3 ) 2 ] and [OsH(Me 2 pymS)(CO)(PPh 3 ) 2 ] (two isomers). A similar reaction in cold benzene affords the substitution product [RuH(Cl)(Me 2 pymSH)(CO)(PPh 3 ) 2 ] (two isomers). Reaction of the precursors [MH 2 (CO)(PPh 3 ) 3 ] (MRu, Os) and [Ru(CO) 3 (PPh 3 ) 2 ] in boiling toluene afford [MH(Me 2 pymS)(CO)(PPh 3 ) 2 ] (two isomers) and [Ru(Me 2 pymS) 2 (CO)(PPh 3 )] (two isomers) respectively whilst the reaction of [Ru(CO) 3 (PPh 3 ) 2 ] with Me 2 pymSSpymMe 2 yields a mixture of [Ru(Me 2 pymS) 2 (CO) 2 (PPh 3 )] and [Ru(Me 2 pymS) 2 (CO)(PPh 3 )]. In the presence of the base (NEt 3 ) the dichlorides [MCl 2 (PPh 3 ) 3 ] (M=Ru, Os) react with Me 2 pymSH to afford the bis-chelates [M(Me 2 pymS) 2 (PPh 3 ) 2 ]. Reactions between Me 2 pymSH and the precursors [IrCl(CO)(PPh 3 ) 2 ] and [IrH(CO)(PPh 3 ) 3 ] at ambient temperature or below afford [IrH(Cl)(Me 2 pymS)(CO)(PPh 3 ) 2 ] and [IrH 2 (Me 2 pymS)(CO)(PPh 3 ) 2 ] respectively, the same ligand reacts with [RhCl(PPh 3 ) 3 ] and mer -[IrH 3 (PPh 3 ) 3 ] in refluxing benzene to afford [RhH(Cl)(Me 2 pymS)(PPh 3 ) 2 ], [Rh(Me 2 pymS) 3 (PPh 3 )], and [IrH 2 (Me 2 pymS)(PPh 3 ) 2 ]. The new complexes have been characterised by infrared and NMR [ 1 H, 31 P{ 1 H}] spectroscopy, and shown to contain monodentate (S-bonded) or chelate (N,S-bonded) Me 2 pymS ligands.

The title compound, prepared by heating [RuHCl(CO)(PPh 3 ) 3 ] with di- isop ropylcarbodiimide (Pr i N=C=NPr i ) in boiling benzene, has been shown by 1 H n.m.r. and X-ray diffraction methods to contain the N- isop ropenyl-N′- isop ropylformamidinate ligand generated by insertion of the carbodiimide moiety into the Ru H bond and the concomitant loss of molecular hydrogen from one of the isop ropyl groups.

Osmium triphenylphosphine complexes, OsH4(PPh3)3, OsH2 (CO)(PPh3)3 and OsHCl(CO)(PPh3)3 react with triphenyl phosphite in boiling organic solvents to yield triphenyl phosphite derivatives which subsequently undergo ortho-metallation reactions.

Labile Olefin- oder Triphenylphosphin-Derivate entsprechender Ubergangsmetallhalogenide reagieren mit Phosphiten, Phosphoniten und Phosphiniten in kalten oder siedenden Alkoholen oder Methylcyanid zu den komplexen Kationen (I)-(IV), die als Tetraphenylborate IR- und NM R-spektroskopisch sowie durch Leitfahigkeitsmessungen charakterisiert werden.

The synthesis and characterization of new benzotriazole (btaH) complexes M(btaHbta)2(btaH)(PPh3) (N2 and N3-btaH linkage isomers), M(btaHbta)H(CO)(PPh3)2 (M = Ru or Os) and IrH2(btaHbta)(PPh3)2, in which the H-bonded benzotriazolate anion—benzotriazole pair (btaHbta)′ functions as a novel N,N′-chelate ligand, are reported. The stereochemistry of the osmium complex Os(btaHbta)H(CO)(PPh3)2 and the nature of the btaHbta moiety therein have been confirmed by an X-ray crystal structure determination.

Rh(O 2 CCF 3 ) 2 (NO) (PPh 3 ) 2 cristallise dans Cc avec Z=4; affinement jusqu'a R=0,085. Ir(O 2 CCF 3 ) 2 (No) (PPh 3 ) 2 .(CH 3 ) 2 CO cristallise dans Pbcn avec Z=8; affinement jusqu'a R=0,082

Alkyl- and aryl-isothiocyanates undergo insertion reactions with platinum metal hydrides to yield the corresponding N -alkyl- and N -aryl-thioformamido derivatives, the structure and stereochemistry of which have been deduced using 1 H NMR data.

Proton NMR spectra of the dithioformate ligands in an extensive range of new platinum metal dithioformato complexes permit unambiguous assignment of stereochemistry.

Reactions of some platinum group metal triphenylphosphine complexes with nitric acid afford nitrato(triphenylphosphine) derivatives in good yield; the complex “Rh(NO3) (NO)2(OPPh3)2” is positively identified as [Rh(NO3)2 (NO) (PPh3)2]

Preparation de complexes MH x Cl y L z (L=PPh 3 ), precurseurs de complexes MCl(pyX)(CO)(PPh 3 ) (M=Ru ou Os, X=O ou S)