Showing papers in "Transition Metal Chemistry in 1977"
TL;DR: In this article, the reaction of cis-PtCl2(R2S)2 under the same conditions with PhLi, with an excess of PhLi orp-tolylLi in ether yielded the dimeric cis-[PtR′2(Et2S)]2 complexes where R′=Ph orp tolyl.
Abstract: Reaction ofcis-PtCl2(R2S)2, where R=Et, n-Pr or i-Pr, with an excess of PhLi orp-tolylLi in ether yielded the dimeric [PtR′2(R2S)]2 complexes where R′=Ph orp-tolyl. Usingtrans-PtCl2(R2S)2 under the same conditions with PhLi, both [PtPh2(Et2S)]2 and PtPh2(Et2S)2 were isolated. The dimericcis-[PtR′2(Et2S)]2 complexes reacted with a range of neutral ligands to give PtR′2L2 where L=Et2S, Me2S, PPh3, t-BuNC, 0.5 (bipyridine) or pyridine. With CO, thecis-PtR′2(Et2S)(CO) compounds were formed. Thecis-Pt(C6F5)2(Et2S)2 complex reacted stepwise with PPh3 and both Pt(C6F5)2(Et2S)(PPh3) and Pt(C6F5)2(PPh3)2 were isolated.
49 citations
TL;DR: In this article, the coordination compounds of copper(II) chloride, bromide, thiocyanate and sulphate with nicotinic acid, nicotinamide and isonicotinamide have been characterized by molecular conductance, magnetic susceptibility, electronic and i.r. spectral measurements.
Abstract: Coordination compounds of copper(II) chloride, bromide, thiocyanate and sulphate with nicotinic acid, nicotinamide and isonicotinamide have been prepared and characterized by molecular conductance, magnetic susceptibility, electronic and i.r. spectral measurements down to 200 cm−1 in the solid state. Possible stereochemistries for these complexes in the solid state are discussed.
32 citations
TL;DR: The MnCl2 (H2 DIP) · 5H2O complex [H2DIP = 2,6-diacetyl-pyridinebis(picolinoylhydrazone)] has been synthesized and examined by i.r.-spectroscopy and x-ray diffractometry as discussed by the authors.
Abstract: The MnCl2 (H2 DIP) · 5H2O complex [H2DIP = 2,6-diacetyl-pyridinebis(picolinoylhydrazone)] has been synthesized and examined by i.r.-spectroscopy and x-ray diffractometry. Crystals are triclinic (P\((P \bar 1)\)) with unit-cell dimensions:α = 15.00(1),b= 13.65(1),c = 7.565(6) A,α = 92.4(1),β = 97.5(1),γ = 117.5(1)°; Z = 2. The structure was solved from 1788 independent diffractometer data by direct methods and refined anisotropically by block-diagonal leastsquares calculations toR = 5.4%. The manganese ion has a distorted pentagonal-bipyramidal geometry, in which the organic molecule acts as a pentadentate ligand. A disordered distribution involving chlorine ions and water molecules is present.
25 citations
TL;DR: In this article, the platinum-platinum bonded [PtR2(OAc)L1]2 complexes (R = Ph, L 1 = Et2S, n-Pr2S; R =p-tolyl, L1 = Et 2S), have been prepared by oxidising [PrR2L1 ]2 with AgOAc or Tl(Oac)3.
Abstract: The platinum-platinum bonded [PtR2(OAc)L1]2 complexes (R = Ph, L1 = Et2S, n-Pr2S; R =p-tolyl, L1 = Et2S), have been prepared by oxidising [PrR2L1 ]2 with AgOAc or Tl(OAc)3. The sulphide ligand is replaced by weak ligands to give [PtR2(OAc)L2]2 (L2 = PhNH2, 4-picoline, CI−) whereas PEt3 or P(OMe)3 react to give Pt2R4(OAc)2(PR′3)(R′ = Et, OMe). The methyl platinum analogues could also be prepared. Similar complexes Pt2Me4(O2CCF3)2L3 (L3 = Et2S1 4-picoline) were obtained by the reaction of Hg(O2CCF3)2 with [PtMe2(O2CCF3)L3]2.31p,1H and13C n.m.r. of the complexes are reported.
24 citations
TL;DR: In this paper, the facile replacement of the OClO3- or Me2CO-groups by a variety of neutral ligands allows the preparation of novel cationic Dicarbonyl complexes, [Mn(CO)3(chelate)LL′]ClO4.
Abstract: In complexes of the Mn(CO)3(chelate)OClO3 and [Mn(CO)3(chel)(Me2CO)]ClO4 type, the facile replacement of the OClO3- or, respectively, Me2CO-groups by a variety of neutral ligands allows the preparation of novel cationic Dicarbonyl complexes, [Mn(CO)3(chelate)LL′]ClO4, at room temperature Dicarbonyl derivatives, [Mn(CO)2(chelate)L2]ClO44 or [Mn(CO)2(chelate)LL′]ClO4, can be obtained by working at the reflux temperature The properties of the novel compounds are given and their structures are discussed
23 citations
TL;DR: In this article, the properties of LMo(CO)s and cis-L2Mo( CO)4 (L = Ph3P1Ph3As and Ph3Sb) derivatives have been studied.
Abstract: Halogen oxidation of several LMo(CO)s andcis-L2Mo(CO)4 (L = Ph3P1Ph3As and Ph3Sb) derivatives has been studied. The LMo(CO)5 complexes react with halogens to give hexacoordinate LMo(CO)3 X2 (X = Cl, Br or I) derivatives which are of very rare occurrence. Similar reactions withcis-L2Mo(CO)4 give heptacoordinate L2Mo(CO)3X2 derivatives. The complexes have been characterised by elemental analysis, i.r. and conductivity measurements.
23 citations
TL;DR: In this article, the tetrahedral geometry is suggested for all the complexes except CoLCl2 and HgCo2 L2 C16 for which tetralithm geometry was suggested.
Abstract: Nicotinoyl hydrazide, L, complexes of the MLCl2 · n EtOH type [M = manganese(II), iron(ll), cobalt(II), nickel(II) and copper(II); n = 0 or 1], WL2) (NO3)2 [M = cobalt(II) and nickel(II)] and mixed metal complexes such as HgCo2 L2 Cl6 and (NiL2)HgI4 have been prepared and their nature and structure studied by molar conductance, magnetic susceptibility, electronic, e.s.r. and i.r. spectral measurements. Octahedral structures have been proposed for all the complexes except MnLCl2, CoLCl2 and HgCo2 L2 C16 for which tetrahedral geometry is suggested.
22 citations
TL;DR: In this article, the Cu2L4X2 and CuL′X complexes were obtained by reduction of copper(II) halides and studied by i.r. spectroscopy in the 4000−200 cm− range.
Abstract: White crystalline complexes of general formula Cu2L4X2 (where X = Cl, Br and L = 1, 3-oxazolidine-2-thione, pyrrolidine-2-thione,N-methyl-1,3-imidazolidine-2-thione andN-ethyl-1,3-imidazolidine-2-thione) and CuL′X (where L′ = 1,3-imidazolidine-2-thione) were prepared by reduction of copper(II) halides and studied by i.r. spectroscopy in the 4000−200 cm− range. Evidence for ligand coordination to the metal through sulphur was found in each case. Theν(CuCI) vibration in all the chloro derivatives falls atca. 240 cm−.
21 citations
TL;DR: In this paper, the copper(II) acetate and picrate complexes of sulfa drugs have been characterized with the help of analytical, electronic, i.r.t. and magnetic moment data.
Abstract: Copper(II) acetate and picrate complexes of sulfa drugsviz., sulfanilamide, sulfaguanidine, sulfathiazole, sulfadiazine, sulfamerazine and sulfamethazine were prepared and characterized with the help of analytical, electronic, i.r. and magnetic moment data. The complexes are paramagnetic, planar or mixed planar and octahedral, insoluble and melt (with decomposition) in the 185°–225° range. The sulfa drugs coordinate through their amino groups and the acetate or picrate ions are bonded to the metal through the -C(O)O group.
21 citations
TL;DR: In this paper, the existence of a pseudobase arising from attack of H2O or HO− at the ligand in tris-(1,10-phenanthroline)nickel(II) was established.
Abstract: Circular dichroism and electronic spectral measurements have established the existence of a covalent hydrate and a pseudobase arising from attack of H2O or HO− at the ligand in tris-(1,10-phenanthroline)nickel(II). In anhydrous solvents and strongly acidic solution, the complex is largely unsolvated. Over a large pH range the dominant species present in aqueous solution is the covalent hydrate while at high pH, this is converted into the pseudo-base. The existence of these species, and the equilibria between them in aqueous solution elegantly explains the pH dependent dissociation and racemization of the parent molecule. It further explains the non-linear variation of these reactions in mixed solvents and indicates that more than one mechanism is responsible over the range of solvents studied here and previously.
19 citations
TL;DR: In this paper, the authors used chiral phosphines under hydrogen as catalysts for the homogeneous hydrogenation of Schiff bases at 30-80° and 1-70 bars.
Abstract: Complexes formed from [Rh(norbornadiene)Cl]2 and tertiary phosphines under hydrogen are active catalysts for the homogeneous hydrogenation of Schiff bases at 30–80° and 1-70 bars. Using chiral phosphines some optical induction can be achieved, but the optical yields are rather low.
TL;DR: In this article, the reaction of zinc(II), cadmium(II) and mercury (II) halides with ethylenselenourea yields complexes of general formula ML2X2 where X = Cl, Br, I.
Abstract: Reaction of zinc(II), cadmium(II) and mercury(II) halides with ethylenselenourea yields complexes of general formula ML2X2 where X = Cl, Br, I. On the basis of an i.r. comparison of these complexes and their ethylenthiourea analogues in the 4000-200 cm−1 range, it appears that the ethylenselenourea complexes are monomeric, tetrahedral and Se-bonded to the metals. The metal-halogen and metal-ligand vibrations above 200 cm−1 are identified.
TL;DR: In this paper, the 3-amino-5-methylisoxazole (3-AMI) ligand was characterized by means of magnetic, spectroscopic and molar conductivity measurements.
Abstract: Cobalt(II) and copper(II) halide, nitrate, thiocyanate and perchlorate complexes of 3-amino-5-methylisoxazole (3-AMI) have been prepared and characterized by means of magnetic, spectroscopic and molar conductivity measurements In Cu(3-AMI)2X2 compounds (X = Cl, Br, N02) the 3-AMI ligand is bridging and bidentate [N (ring), O(bonded)] In the other derivatives it is monodentate [N(ring) bonded] All cobalt(II) complexes have an octahedral stereochemistry, if the Co(3-AMI)2X2 derivatives (X = Cl, Br), which are tetrahedral, are excluded Copper(II) complexes have generally a distorted square pyramidal stereochemistry in the solid state and in solution
TL;DR: In this article, the structure of acetone nicotinoyl hydrazone (ANII) complexes of the types M(ANH)Cl2 · nEtOH and M (ANH-H)2 H2O has been studied by magnetic and electronic spectra and room temperature magnetic measurements.
Abstract: Acetone nicotinoyl hydrazone (ANII) complexes of the types M(ANH)Cl2 · nEtOH and M(ANH-H)2 H2O (where M = MnII FeII, CoII, NiII, CuII or ZnII and n = 0,1 or 2) have been prepared and their structures studied by molar conductance, i.r. and electronic spectra, and room temperature magnetic measurements. All the complexes arc nonionic in a 0.001 M solution of formic acid. Magnetic and electronic spectral studies show that all the complexes are spin-free regular or distorted octahedra except Mn(ANH)Cl2 and Co(ANH)CI2 which are tetrahedral. The distorted octahedral geometry of Cu(ANH-H)2 · H2O has also been confirmed from its sold state e.s.r spectrum at 77 K. From i.r. spectral studies, ANH has been found to act as a tridentate ligand in all the complexes except Mn(ANH)Cl2 where it behaves as a bidentate ligand.
TL;DR: In this article, the authors synthesize and characterize debp-2(OClO3)n+ tris-chelate cationic complexes with 3D metal perchlorates using spectral, magnetic susceptibility and conductance measurements.
Abstract: Complexes (2 : 1) of diethyl benzoylphosphonate (debp) with 3d metal perchlorates were synthesized and characterized by means of i.r. and electronic spectral, magnetic susceptibility and conductance measurements. In new complexes of the types [M(debp)2(OClO3)(OH2)](ClO4) (M = Fe, Co, Zn) and [Fe(debp)2(OClO3)(OH2)](ClO4)2, both debp ligands function as bidentate chelating agents, coordinating through the P=O and C=O oxygens. In contrast, in the manganese(II) and nickel(II) complexes, which are of the [M(debp)2(OClO3)(OH2)2](ClO4) type, one debp acts as a bidentate chelating ligand, while the second debp is unidentate, coordinating only through the P=O oxygen. Hexacoordination in the new cationic complexes is completed by coordination of aqua and unidentate perchlorato ligands, which are in competition for sites in the inner coordination sphere of the central metal ion with the weak debp ligand. On the other hand, debp, owing to its bulkiness, and especially the presence of the benzoyl substituent, introduces sufficiently severe steric hindrance during coordination. As a result of this, the formation of [M(debp)3]n+ tris-chelate cationic complexes with the 3 d metal ions under study does not seem to be possible.
TL;DR: The Schiff bases RC(OH)=CHC(R′)=NNMeC(S)SMe (R = Ph,p-MeC6H4,R′ = Me; R = R′ = Ph) have been prepared by condensation of β-diketones with α-N-methyl-S-methyldithiocarbazate as mentioned in this paper.
Abstract: The Schiff bases RC(OH)=CHC(R′)=NNMeC(S)SMe (R = Ph,p-MeC6H4, R′ = Me; R = R′ = Ph) have been prepared by condensation of β-diketones with α-N-methyl-S-methyldithiocarbazate. By the loss of a proton they act as singly negatively charged tridentate ligands with oxygen, nitrogen and sulphur donor atoms (ONS). Iron forms the high-spin complexes [FeIII(ONS)2][FeIIICl4]. Copper(II), palladium(II), and platinum(II) yield the square-planar 1 : 1 complexes, M(ONS)CI (M = Cu, Pd, Pt) and Cu(ONS)NO3. Cobalt(II) and nickel(II) form high-spin, six-coordinate 1 : 2 complexes, M(ONS)2. For M = Ni and R = R′ = Ph, the complex is high-spin and octahedral, but when R = Ph orp-MeC6 H4 and R′ = Me, the complexes are diamagnetic and square-planar with nitrogen and sulphur (NS) coordinatio of the Schiff base, indicating that a change in the R′group can bring about a change in spin-state and stereochemistry of nickel.
TL;DR: In this article, a bis-(2,2′-bipyridyl)platinum(II) ion has been shown to be highly reactive towards methoxide ion, and the dissociation of a 2,2'biparidyl ligand is preceded by attack at the ligand.
Abstract: Bis-(5-nitro-1,10-phenanthroline)platinum(II) dichloride and diperchlorate have been prepared. The reaction between the parent cation and hydroxide ion has been studied using 1 FI n.m.r. spectroscopy and found to involve attack at the ligand. The bis-(2,2′-bipyridyl)platinum(II) ion has been shown to be highly reactive towards methoxide ion. The dissociation of a 2,2′-bipyridyl ligand is preceded by attack at the ligand.
TL;DR: In this paper, the bonding mode of the triazenido ligand is monodentate in the (ν5-C5H5)(L)(RN3R)Ni and (ν 5-C 5H5)Pd compounds, with L = PPh3, CO, CNR′, and RN3R = diaryltriazenid anion, were prepared.
Abstract: The (ν5-C5H5)(L)(RN3R)Ni and (ν5-C5H5)(PPh3)(RN3R)Pd compounds, with L = PPh3, CO, CNR′, and RN3R = diaryltriazenido anion, were prepared. The bonding mode of the triazenido ligand is monodentate in the (ν5-C5H5)(PPh3)(RN3R)M phosphine compounds. The carbonyl and isonitrile groups are inserted into the nickel-nitrogen bond and a five-membered heteronuclear ring is formed in (ν5-C5-C5H5)(L)(RN3R)Ni, when L= CO and CNR′. Most compounds are fluxional, involving site exchange of the triazenidoaryl-groupsvia intermediates with a chelating bonding mode of the triazenido ligand. The (ν5-C5H5)(PPh3)(RN3R)Ni compound shows anomalous solution paramagnetism, that is correlated with the fluxional mechanism. The temperature dependence of contact shifts in the n.m.r. spectrum was determined and ΔE-values were calculated.
TL;DR: In this paper, the spectral properties of PdCl2 or [PdCI4]2− in nonpolar solvents and phosphines R2PH or RPH2 were characterized by their spectral properties.
Abstract: Reactions between PdCl2 or [PdCI4]2−, in nonpolar solvents and phosphines R2PH or RPH2 (R = cyclohexyl, 2-cyanoethyl) yield new complexes ofcis- L2PdCl2 type, which were characterized by their spectral properties. In polar solvents these complexes react further to give bridged µ-phosphido complexes. Analogous bromides can be prepared by adding LiBr to the reaction mixtures.
TL;DR: In this article, the chelating behavior of metal complexes of three different organic molecules in relation to the different geometry of the ligand and to the nature of the metal and of the counter-ion has been examined and compared.
Abstract: The chelating behaviour of the
system has been examined and compared in metal complexes of three different organic molecules in relation to the different geometry of the ligand and to the nature of the metal and of the counter-ion. Bond distances and angles, planarities, and vibrational bands of the system are discussed and correlated.
TL;DR: In this paper, N-benzamidosalicylaldimine (H2L) complexes of CuII, NiII, CoII, FeII, MnII have been prepared and the ligand probably coordinates to the metal from the hydroxyl, carbonyl and imino groups.
Abstract: N-benzamidosalicylaldimine (H2L) complexes of CuII, NiII, CoII, FeII, MnII. VOIV and TiOIV have been prepared. The ligand probably coordinates to the metal from the hydroxyl, carbonyl and imino groups.
TL;DR: In this article, the ZnII, CdII and HgII complexes of sulfadrugs, i.e., sulfathiazole, sulfadiazine, sulfamerazine and sulfamethazine, were characterized by analytical and spectroscopic data.
Abstract: ZnII, CdII and HgII complexes of sulfadrugs,viz., sulfathiazole, sulfadiazine, sulfamerazine and sulfamethazine were prepared and characterized by analytical and spectroscopic data. The complexes are insoluble and melt with decomposition. The drugs act as bidentate ligands yielding polymeric complexes except for the ZnII(sulfamethazine) complex in which the drug is monodentate.
TL;DR: In this paper, the synthesis of ketones from bis(1,5-cyclooctadiene)nickel(0) and aroyl halides containing ortho-substituents is described.
Abstract: Facile syntheses of ketones have been achieved starting from bis(1,5-cyclooctadiene)nickel(0) and aroyl halides containingortho-substituents. Electrophilic or nucleophilic attack of aroyl groups upon organic substrates also give rise to other classes of ketones.
TL;DR: In this paper, the structures in solution of a series of palladium(II) complexes have been determined by 1H n.m.r. spectroscopy and i.i.d.
Abstract: The structures in solution of a series of palladium(II) complexes have been determined by1H n.m.r. and i.r. spectroscopy. Dicyanobis-(8-hydroxyquinoline)palladium(II) has acis-square-planar configuration, the unidentate 8-hydroxyquinoline molecules bonding to Pd through the nitrogen atoms. Dicyanobis-(2,9-dimethyl-1,10-phenanthroline)-palladium(II) has acis-square planar arrangement about Pd with respect to the nitrogen atoms of the two heterocyclic ligands. The cyanide groups bond to the two apical positions apparently giving rise to a six-coordinate PdlI atom. Dihalo-2,9-dimethyl-1,10-phenanthrolinepalladium(II) (X = Cl, Br, I) exhibits the usualcis-square-planar arrangement of PdII, whereas the halobis-(2,9-dimethyl-1,10-phenanthroline) - palladium(II) ion (X = Cl, Br) has a trigonal bipyramidal structure with the halogen atom in the trigonal plane.
TL;DR: The Schiff bases have been shown to have a polymeric structure involving σ-thiolo-bridges and can be used to give dimeric µ2-dithiolo -bridged complexes.
Abstract: The Schiff bases RC(OFl)=CFlC(CF3)=NNlJC(S)NH2 (R = 2-thienyl, Ph,p-BrC6H4,p-MeC6H4,p-MeOC6H4,m-McOC6H4, β-naphthy], Pri) have been prepared by condensation of fluorinated β-diketones with thiosemicarbazide. By the loss of one or two protons from their tautomeric iminothiol form RC(OH)=CHC(CF3)=NN=C(SH)NH2 the Schiff bases act as (i) doubly negatively charged ONS tridentate or (ii) singly negatively charged NS bidentate ligands, respectively. The Schiff bases give dimeric µ2-dithiolo-bridged complexes M(ONS)2 (M = Ni, Pd, and Pt). The thiolo-bridges in the nickel complexes can be split by reaction with pyridine to give the monomeric compounds Ni(ONS)py, whereas the palladium and platinum complexes are unreactive towards pyridine. When R = 2-thienyl orp-BrC6H4, 1:2 complexes of the type M(HONS)2 (M = Pd or Pt) were isolated. With copper(II) the Schiff bases yield the complexes CuII(ONS). CuI(HONS) which are considered to have a polymeric structure involving σ-thiolo-bridges.
TL;DR: Some rhodanine (HL) complexes of silver(I) and gold(1) have been prepared and studied by conductivity measurements and by i.r. spectroscopy as discussed by the authors.
Abstract: Some rhodanine (HL) complexes of silver(I) and gold(1) have been prepared and studied by conductivity measurements and by i.r. spectroscopy. Structures for the complexes are proposed.
TL;DR: In this article, the reaction of 1,3-thiazolidine-2-thione and copper(II) chloride and bromide in MeOH yields CuL3X complexes.
Abstract: Reaction of 1,3-thiazolidine-2-thione and copper(II) chloride and bromide in MeOH yields CuL3X complexes. These react with an excess of copper(II) halide to give CuL2X complexes. From their i.r. spectra, all the complexes seem to be S-bonded to the metal. Thev(CuCl) vibration is identified at 236 cm−1.
TL;DR: In this paper, the results support the earlier findings that these reactions proceed through the formation of pseudo-bases with the ligand, and they also show that the pseudo-base formation occurs through formation of pseudobases with a ligand.
Abstract: The reactions between Ho−, CN−, MeO− and EtO− and Δ-(-)-tris-(5-vitro-1,10-phenantliroline)ruthenium(II) ion in solution were followed by c.d. measurements. The results support the earlier findings that these reactions proceed through the formation of pseudo-bases with the ligand.