Showing papers on "Denticity published in 1974"
TL;DR: The tendency toward mixed complex formation may be expressed quantitatively in two different ways as mentioned in this paper : the most common approach is to compare the stability of the mixed complex with the two pure 2:1 complexes where two like ligands are bound to a single metal ion.
103 citations
TL;DR: In this paper, a 2,2′-bipyridine and 1,10-phenanthroline-mono-Noxide (bipyNO and phenNO, respectively) chelates with Cr(III) and Fe(III)-perchloratws were synthesized and characterized by means of spectral, magnetic and conductance studies.
77 citations
TL;DR: In this paper, the synthesis, physico-chemical propperties and crystal structure of two new isomorphous π-allyldicarbonyl trifluoroacetates, solvated by 1,2-dimethoxyethane, are reported.
55 citations
TL;DR: Cochinative interactions of DOPA, dopamine, adrenaline, noradrenaline and tyramine with H+, Ni2+, Cu2+, Zn2+, Cd2+ and Pb2+ have been studied by the pH-titration method at 20°C.
51 citations
TL;DR: In this paper, the planar carbonate ions bridge in an unusual manner, each being bidentate to one molybdenum atom and monodentate to the other.
Abstract: Carbon dioxide reacts with cis-[Mo(N2)2(PMe2Ph)4] to form a complex [Mo(CO2)2(PMe2Ph)4] which changes spontaneously in solution into a carbonato-bridged complex, [(PMe2Ph)3(CO)Mo(CO3)2Mo(CO)(PMe2Ph)3], the structure of which has been determined; the planar carbonate ions bridge in an unusual manner, each being bidentate to one molybdenum atom and monodentate to the other.
45 citations
TL;DR: In this paper, the interactions of the oxo-centred ruthenium(III) acetate, [Ru3O(CO2Me)6(MeOH)3] CO2Me or species formed from it by reduction, with carbon monoxide, methyl isocyanide, sulphur dioxide, and nitric oxide have been studied.
Abstract: The interactions of the oxo-centred ruthenium(III) acetate, [Ru3O(CO2Me)6(MeOH)3]CO2Me or species formed from it by reduction, with carbon monoxide, methyl isocyanide, sulphur dioxide, and nitric oxide have been studied. Only a monocarbonyl, e.g., Ru3O(CO2Me)6(CO)(py)2 is formed and the six bridged carboxylate groups of the original oxo-centred species rearrange to give two bridged and four bidentate carboxylate groups. The complexes have been studied, where feasible, by i.r. and n.m.r. spectroscopy and their electrochemical behaviour investigated. The mean oxidation state for ruthenium of 2⅓(or II, II, III) in a trinuclear complex has been characterised. The complexes Ru(CO)(CO2Me)2(PPh3)2 and Ru(MeNC)2(CO2Me)2(PPh3)2 are described; the former has one bidentate and one monodentate acetate and appears to be a non-rigid molecule. Bis- and tris-isocyanide complexes were obtained, with acetate and propionate respectively, and mononitrosyl and sulphur dioxide complexes were prepared.
44 citations
37 citations
TL;DR: In this article, the preparation of 8 bis(pentaflurophenyl) complexes of Pd 11 and of Pt 11 with monodentate and bidentate nitrogen-donor ligands is described together with a preparation of a Pd11 complex of 1,2-bis(diphenylphosphino)ethane.
34 citations
TL;DR: In this article, the tridentate NNS Schiff bases 1-(pyrid-2-ylmethylene)-2-methylthiosemicarbazide C5H4NCHNN
33 citations
TL;DR: The crystal structure of the title compound has been determined from three-dimensional X-ray data by Patterson and Fourier methods, and refined by least-squares techniques to R 0·089 for 4080 visually estimated independent reflections as discussed by the authors.
Abstract: The crystal structure of the title compound has been determined from three-dimensional X-ray data by Patterson and Fourier methods, and refined by least-squares techniques to R 0·089 for 4080 visually estimated independent reflections. Crystals are monoclinic, with unit-cell dimensions a= 20·68(4), b= 9·639(20), c= 26·59(4), β= 119·58(8), space group is P21/c and Z= 4.The complex is monomeric and the metal atom has a highly distorted octahedral co-ordination. The three triphenylphosphine ligands are meridional and the hydride hydrogen atom is cis to all three. Ru–P bond distances for the two approximately trans PPh3 groups (2·363, 2·351 A) are appreciably longer than the third (2·230 A); Ru–H is ca. 1·7 A. The acetate group is bidentate and weakly held, with two rather long Ru–O distances (2·198 and 2·210 A). It subtends an angle of 57·6° at the ruthenium atom.
31 citations
TL;DR: The crystal structure of 1,10-phenanthroline was determined and refined to an R-value of 0.051 in this article, where the coordination number and geometry were discussed in terms of 5coordinate tetragonal pyramidal and 4-coordinate square planar models.
Abstract: The crystal structure of cis-chlorobis(triethylphosphine)-1,10-phenanthrolineplatinum(II) fluoroborate has been determined and refined to an R-value of 0.051. The space group is P21/c and the cell dimensions are a = 0.9215(2), b = 1.1991(3), c = 2.6832(6) nm, β = 99.38(3)°, with 4 molecules per unit cell. The interatomic distances to Pt are: Pt—N(1), 213.7(19); Pt—N(2), 284.3(20); Pt—P(1), 223.9(7); Pt—P(2), 224.1(6); Pt—Cl, 236.1(6) pm.The coordination number and geometry is discussed in terms of 5-coordinate tetragonal pyramidal and 4-coordinate square planar models, the latter being regarded as the more acceptable.Monodentate o-phenanthroline is thus observed for the first time in the solid state. The structure of the complex in solution is discussed with the aid of conductance and nuclear magnetic resonance results which suggest the possibility of a novel fluxional system.
TL;DR: Mass spectrometry has been used to investigate the interaction of a number of cis - and trans -Pt(amine) 2 Cl 2 complexes with nucleoside analogues but little evidence has been derived to confirm the structure of the linkage.
TL;DR: In this article, the synthesis of divalent 3D metal nitrate complexes with 2,2′-bipyridine N-oxide and 1,10-phenanthroline Noxide (N-phenO) is reported.
TL;DR: In this article, the metal donor atom core electron binding energies have been measured for seven related polydentate Schifr base complexes of nickel(II) and copper(II), and the potential donor atoms of all neutral ligands except one and the free metals were also studied.
TL;DR: In this paper, the relative reactivities of CO and CNCH3 ligands with amines are discussed, and factors affecting their relative reactivity with amine amine are discussed.
Patent•
13 Mar 1974TL;DR: A mixture of catechol and hydroquinone is prepared by oxidizing phenol in an aqueous medium with hydrogen peroxide at a pH of 6.0 or lower in the presence of a catalyst consisting of at least one organic metal coordinate compound which is prepared from a salt of a metal selected from the class consisting of iron, copper, chromium and cobalt.
Abstract: A mixture of catechol and hydroquinone is prepared by oxidizing phenol in an aqueous medium with hydrogen peroxide at a pH of 6.0 or lower in the presence of a catalyst consisting of at least one organic metal coordinate compound which is prepared from a salt of a metal selected from the class consisting of iron, copper, chromium and cobalt and an organic ligand compound selected from the class consisting of aromatic chelating compounds, heterocyclic monodentate coordinating compounds, heterocyclic polydentate chelating compounds and aliphatic chelating compounds, when one of the coordinate bonding groups in the aliphatic chelating compound is the carbonyl group, the remaining coordinate atoms or groups are other than the carbonyl group, and isolating the resulting catechol and hydroquinone from the oxidation admixture.
TL;DR: In this paper, the kinetic parameters of the hindered rotation around the bonds in the gold complexes have been determined from n.m. spectra, and the values for the activation energies have the same order of magnitude as those found for other hindered rotation processes in dithiocarbamate complexes.
TL;DR: In this paper, photo-induced nitrosylation of Mn 2 (CO) 10 in n-pentane solution results in the formation of Mn(NO) 3 CO via Mn(CO) 4 NO, while complete decarbonylation is observed in tetrahydrofuran.
TL;DR: In this article, the structures of these complexes were identified on the basis of vibrational (conventional and far infrared) and electronic spectroscopy, magnetism and conductivity measurements, the bonding occurs through the oxygen in the complexes of thiomorpholin-3-one and through the nitrogen in all the remaining complexes.
Abstract: Complexes of thiomorpholin-3-one, thiomorpholin-3-thione, thiazolidine-2-thione, and thiazolidine-2-selenone with CrX3•nH2O (X = Cl, Br, I) were prepared and characterized. On the basis of vibrational (conventional and far infrared) and electronic spectroscopy, magnetism and conductivity measurements, the structures of these complexes were identified. The bonding occurs through the oxygen in the complexes of thiomorpholin-3-one and through the nitrogen in all the remaining complexes. The complexes crL3x3 involve unidentate ligands, are neutral, monomeric, and hexacoordinate. Spectroscopic parameters for the complexes have been calculated and compared with similar chromophores containing CrN3X3, CrO3X3, and CrS3X3 chromophores.
TL;DR: The perchlorato ligand of perchloratobis(pentafluorophenyl)triphenylphosphinegold(III) can easily be displaced by different types of ligands.
TL;DR: In this article, a partition of the SCF binding energy of Li + with formaldehyde into its Coulomb, exchange and delocalization contributions is performed and discussed at various distances and angles.
TL;DR: A series of cobalt(III) complexes of 2,12-dimethyl-3,7,11,17-tetraazabicyclo(11.3.1)heptadeca-1 (17),2,11-13,15-pentaene, CR, has been prepared as discussed by the authors.
Abstract: A series of cobalt(III) complexes of 2,12-dimethyl-3,7,11,17-tetraazabicyclo(11.3.1)heptadeca-1 (17),2,11,13,15-pentaene, CR, has been prepared. In addition to materials of common compositions and structures, the series includes a diiodo complex, a complex containing a bidentate nitrate ligand, an NO− derivative, and one in which ethylenediamine acts as a monodentate ligand with a dangling, unprotonated primary amine group.
TL;DR: Several new complexes of general forms, such as [Rh(bhq)2LX] as mentioned in this paper, were obtained by reactions of [Rbq2Cl]2 · 1 4 CHCl3 with monodentate and bidentate ligands, and were characterized by means of conductivities, and PMR and IR spectra.
TL;DR: In this article, the coordination of the N-acetylglycine occurs only through the terminal carboxyl oxygen in a monodentate arrangement, while for the piperazine and ethylenediamine adducts a squareplanar pattern of coordination about copper(II) ion is probable.
Abstract: Compounds of the type [CuA2•H2O]2 and [CuA2•4H2O]2 have been prepared, where A is N-acetylglycine (aceturic acid). Amine adducts of the type CuA2B (B = piperazine, 2,2′-bipyridine, and 1,10-phenantroline) and CuA2B2 (B = N-methylpiperazine, piperidine, morpholine, pyridine, and ethylenediamine) were obtained by reaction of the amines with CuA2•4H2O. Each complex was characterized by elemental analysis, infrared spectrum, electronic spectrum, and magnetic moment. For the piperazine and ethylenediamine adducts a square-planar pattern of coordination about copper(II) ion is probable, while for the other amine adducts a square-pyramidal structure is proposed. For all the complexes the coordination of the N-acetylglycine occurs only through the terminal carboxyl oxygen in a monodentate arrangement.
TL;DR: In this paper, the complex ion [Co(mal)2(tn)]- (mal =malonate ion) and the corresponding complexes of trimethylenediamine (tn) containing the bidentate O-donor ligands C2O4 2- and acetylacetonate (acac) ions were prepared and resolved.
Abstract: The complex ion [Co(mal)2(tn)]- (mal =malonate ion) and the corresponding complexes of trimethylenediamine (tn) containing the bidentate O-donor ligands C2O4 2- and acetylacetonate (acac) ions were prepared and resolved. Their circular dichroism (CD) spectra are compared with the data reported here for [Co(C2O4)2(I-chxn)]−, [Co(mal)2 (I-chxn)]−, [Co(mal)2(I-pn)]−, and [Co(acac)2(I-pn)]+ complex ions. The malonate complexes reveal greater splitting within the first absorption band region compared to C2O4 2- and acac, but lower net rotational strengths. The contributions to the CD spectra for the optically active ligands are comparable to those reported for other complexes. There is a much greater contribution from the optically active ligand in trans-cyclohexanediaminetetraacetatocobaltate ion than in the corresponding complex of 1,2-propanediaminetetracetatocobaltate ion.
TL;DR: In this article, the synthesis of divalent 3 d metal perchlorate chelates with 1,10-phenanthroline mono-Noxide (phenNO) was reported.
TL;DR: A series of nickel(0)-stilbene complexes has been prepared by the reaction of triarylphosphines or tert-butyl isocyanide with bis(1,5-cyclooctadiene)nickel(0) in hexane as mentioned in this paper.
TL;DR: In this article, the electronic absorption spectra of the benzeneseleninate anion were studied and values of the spectral parameters were determined, and it was shown that the complexes are seleninato O, O ′ with the ligand bidentate with a distorted octahedral D 4 h symmetry.
TL;DR: The photochemical reactions of the potentially tridentate ligand Triphos, (Ph 2 PCH 2 CH 2 ) 2 PPh, with C 5 H 5 Mn(CO) (Triphos) (two isomers) and C 5H 5 Mn (CO) 2 (CS) in benzene solution at 0° are described in this paper.