Organometallic complexes containing thiosemicarbazone and related ligands. Part II(1). η3-allyl dicarbonyl complexes of molybdenum(II) with attached thiosemicarbazone ligands

Summary The -allylmolybdenum(II) complexes [MoX(CO)₂-(NCMe)₂(³-C₃H₄R)] (X=Cl, Br and I; R=H and 2-Me) react either in dichloromethane or acetonitrile with thiosemicarbazones to give the new complexes [MoX-(CO)₂(RRCNNHCSNH₂)(³-C₃H₄R)] (R=H or Me; R'=Me, Et, Pr or Ph)via displacement of acetonitrile ligands.     

Influence of solvent on ir spectra of aroyl(hydroxymethyl)trifluorosilanes

Conclusions Dipole-dipole interaction of the solvent with molecules of aroyl (hydroxymethyl) trifluorosilanes 4-XC₆H₄COOCH₂SiF₃ is responsible for changes in frequency of the stretching vibrations of groups included in a five-membered ring, containing an intramolecular coordination bond Si 0 (the frequencies C=O and SiF _a , are lowered, and the frequencies _asCOC are raised). The value of the orientation-induction parameter in the Buckingham equation, reflecting the dependence of C=O and SiF _a on the parameters of the medium (, n), increases with increasing electron-donor capability of the substituent X, indicating an increase in the strength of the coordination bond. The coefficient in the Hammett equation is determined by the polar properties of the medium.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2251–2254, October, 1984.     

Inclusion Compounds of NaI with 13-Membered Azo- and Azoxycrown Ethers

Sodium iodide complexes of 13-membered azo-(I)and azoxycrown ethers (II) have been synthesized. Compound I[Na(L1 trans)2]IH2O is triclinic witha = 11.53(2), b = 15.74(2), c = 19.17(2) Å, = 98.93(9), = 105.51(9), = 89.20(9) deg.; Z = 4, space groupP1. Compound II [Na(L2)2]I is orthorhombic witha = 12.451(2), b = 13.796(3), c = 18.667(4)Å; Z = 4, space group P2₁2₁2₁. In bothcomplexes the cation is coordinated tochain oxygen atoms and to one nitrogen atom of the azoor azoxy unit. The ability of bothligands to form complexes in relation to thegeometry of the azo or azoxy subunit of themacrocycle is discussed.     

Synthesis and magnetic properties of copper(II)-cobalt(II) complexes ofN,N′-1,2-propanedisalicylamidatocuprate(II)

Summary The binuclear metal complexes [Cu(sampn)Co(L)₂] (L=bipy, phen), have been prepared by the reaction of sodiumN,N-1,2-propanedisalicylamidatocuprate(II) heptahydrate, Na₂[Cu(sampn)] 7H₂O, with a divalent metalion, and 2,2-bipyridine or 1, 10-phenathroline. The complexes were characterized by variable-temperature magnetic susceptibility measurements; the results indicate that a weak antiferromagnetic spin-exchange interaction operates between the metal ions.     

Synthesis and Crystal Structure of a New Copper–PMIDA Compound (H4PMIDA=H2O3PCH2N(CH2CO2H)2)

A new Cu(II)PMIDA compound [Cu(H₂PMIDA)(phen)] 3H₂O (1) (H₄PMIDA = H₂O₃PCH₂N (CH₂CO₂H)₂,phen = 1,10-phenanthroline) has been successfully synthesized and structurally characterized. In complex 1, Cu (II) is six coordinated by chelation in a tetradentate fashion by a PMIDA ligand and by two N atoms of a phen ligand. Every phen–Cu(II)–PMIDA group connects with each other via a hydrogen bond and the edge-to-face -stacking interaction. Complex 1 crystallized in triclinic P-1 with cell dimensions of a = 7.5817(6) Å, b = 10.6980(8) Å, c = 13.1852(10) Å, =82.350(2)°, = 84.151(2)°, =78.4250(2), V= 1035.25(14) ų, Z = 2, Dc = 1.677 Mg/m³.     

Medium effects on the reactions of coordination complexes: Base hydrolysisof(αβS)(p-hydroxybenzoato)(tetraethylenepentamine) cobalt(III) in iso-propanol–water,tert-butanol–water and dimethyl sulfoxide–water media

The base hydrolysis of (S)(p-hydroxybenzoato)-(tetraethylenepentamine)cobalt(III) has been investigated in aqueous–organic solvent media using i-PrOH, t-BuOH and dimethyl sulfoxide (DMSO) as cosolvents at 20.0 T (°C) 40.0 (I=0.02 mol dm ^-3) with 80% (v/v) of cosolvents. Only the base-catalysed path (k_obs=k_OH[OH^-]) is observed. The relative second order rate constant k _OH ^os /k _OH ^ow at I=0 increases nonlinearly with increasing mol fraction (x_O.S.) of the cosolvents, the rate acceleration in alcoholic cosolvents being greater than in DMSO. The destabilization of ^-OH in mixed solvent media alone does not explain the observed rate acceleration. The solvent composition dependence, log k _OH ^os = log k _OH ^ow + a_ix _os ⁱ [i=1,2,k _OH ⁰ denotes k_OH at I=0 in mixed solvent(s) and water (w)] indicates specific solute–solvent interactions. The values of the relative transfer free-energy data [_TG(t.s.) - _TG^o (i.s.)](sw)(25 °C)(G), where t.s. and i.s. denote the transition state and initial state of the substrates respectively, are positive for all substrates at all compositions, indicating a greater destabilizing effect of the mixed solvent on the transition state than on the initial state. The G values also correlate with G^E(G = ax_O.S. + cG^E) for all solvents, supporting the fact that solvent structural effects mediate the rates and energetics of the reaction. However, the solvent effects on the solvation components of H and S are mutually compensating, thus indicating that there is no change in the mechanism.     

Correlation of volumes and entropies of activation for oxidation of coordinated sulfur in bis-ethylenediaminecobalt(III) complexes by peroxodisulphate,hydrogen peroxide and periodate and for peroxodisulphate oxidation of diimine-cyanide–iron(II) complexes

Activation parameters H , S and V and correlations between S and V are reported for peroxodisulphate oxidation of [Fe(CN)₆]^4–, [Fe(bipy)₃]²⁺ (bipy = (2, 2-bipyridyl), [Fe(phen)₃]²⁺ (phen = 1,10-phenanthroline), cis-[Fe(bipy)₂(CN)₂], [Fe(bipy)(CN)₄]^2–, [Fe(phen)(CN)₄]^2–, [Co(en)₂(glyS)]⁺ (glyS = mercaptoacetate, SCH₂COO^2–), [Co(en)₂(cyS)]⁺ (cyS = cysteinate, SOCH₂CH(COO)NH₂ ^2–) and [Co(en)₂(amS)]²⁺ (amS = ethanesulphenaminate, SCH₂CH₂NH₂ ^–) and for periodate and hydrogen peroxide oxidation of the three last-named complexes. Activation parameters are discussed in terms of electrostriction, solvation and ligand size contributions. Opposite trends for S /V correlations were found for oxidations of Fe^II complexes in comparison with oxidations of coordinated sulphur in the Co^III complexes.     

Crystal structure of copper(I) chloride π-complexes with diallylamine: (C6H12N)2Cu7Cl9·H2O and 2CuCl·C6H11N

For the first time we have synthesized and studied by X-ray structural analysis two novel copper(I) chloride -complexes with diallylamine (DAA): [H(DAA)]₂Cu₇Cl₉·H₂O (D) and 2CuCl·DAA (E). Compound D is isostructural to the complex [H(DAA)]₂Cu₇Br₉·H₂O studied earlier: space group Pnam, a=15.934(8), b=14.817(6), c=11.368(6) , V=2684(4) ³, and Z=4 for [(C₆H₁₂N)₂ Cu₇Cl₉·H₂O]. Crystals E are triclinic: space group P1, a=7.373(2), b=9.743(4), c=11.351(8) , =84.05(4), =101.26(4), =103.31(3)°, V=914(2) ³, and Z=2 for [Cu₄Cl₄·(C₆H₁₁N)₂]. The layers of the structure are formed by combining the armchair-shaped cycles Cu₄Cl₄ via the tridentate DAA molecules.I. Franko Lvov State University, Ukrainian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 34, No. 6, pp. 43–48, November–December, 1993.Translated by T. Yudanova     

Structure of the 18-Crown-6 Complex with Ammonium Hexafluorosilicate and Water

The crystalline host–guest type complex [(18-crown-6NH₄)₂][SiF₆]4H₂Ohas been obtained as the result of the interaction of SiF₄2NH₃ with 18-crown-6 (18C6) in an aqueous medium. Crystal data: monoclinic, space groupC 2 c, a=26.541(2), b=8.363(2), c=20.469(2) Å, = 122.43(1)°and Z=4. The final R-value is 0.070 for 3253 reflections with I 2(I).The crystals consist of the complex [NH₄18C6]⁺ cations, [SiF₆]^2-anions and water molecules. The ammonium cation is hydrogen bonded by three of its H-atoms to the crown ether oxygen atoms with N(1) O separations2.923(5)–2.940(5) Å and by the fourth H-atom to the fluorine atom of thehexafluorosilicate anion, the N(1)F(4) distance being 2.797(6) Å.The conformation of the macrocycle and the hydrogen-bond geometry in thecomplex cation closely resemble those in related adducts between 18-crown-6and ammonium salts. All crystal components are connected via a system of hydrogen bonds into a ribbon along the b axis in the unit cell.     

Calixcrown Binding to Caesium – X-Ray Structural Determination of a 1,3-Alternate Calix[4]arenebiscrown-7 Ligand

The crystal structure of calix[4]biscrown-7, 1, (C₅₂H₆₈O₁₄), (triclinic,space group P1, Z = 2, a = 11.115 (5), b = 11.710 (5), c = 18.990 (7)Å, = 85.12 (4), = 93.11 (5), = 91.01 (5)4°,V = 2458.9 ų, Rw = 0.0737 for 4170 observed, I 3 (I),reflections) has been determined. It is suggested that the polyether loopswith a radius of ca. 2.1 Å are too shallow to efficiently complex theCs⁺ cation (radius = 1.69 Å).