Palladium(II) and Platinum(II) Complexes of N-Phenyl- and N-Ethyl-N′-pyrimidin-2-ylthiourea

Palladium(II) and platinum(II) complexes of N-ethyl-N′-pyrimidin-2-ylthiourea(HL¹) and N-phenyl-N′-pyrimidin-2-ylthiourea (HL²) have been prepared, and the complexes [M(HL)Cl₂], [Pt(L)₂], [Pd(HL¹)₂]Cl₂, and [Pd(L²)₂] (where M = Pd^II or Pt^II) were characterized. The spectroscopic data are consistent with coordination of thioureas as neutral or monoanionic ligands to Pd^II and Pt^II through S and a pyrimidine-N. The IR spectra show shifts of CS and pyrimidine ring stretch bands to lower and higher frequencies, respectively. The ¹H NMR spectra differentiate between H(4′) and H(6′) resonances and indicate downfield shifts for all protons of pyrimidine [H(4′), H(5′), and H(6′)], two resonances for two N?H protons for complexes containing the neutral ligand (HL), and only one N?H proton chemical shift for complexes containing the monoanion (L). ¹³C NMR chemical shifts of pyrimidine carbons are correlated with the type of bonding between Pd^II or Pt^II and pyrimidine-N. The magnetic susceptibilities suggest a diamagnetic planar structure for all complexes.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

β-diketone complexes of manganese(II), cobalt(II), nickel(II) and palladium(II)

Summary The reactions of manganese(II), cobalt(II) and nickel(II) acetates (1 mole) with antipyrine-4-azo--ethylcyanoacetate (HL¹) and antipyrine-4-azo--acetylacetone (HL²) (1 mole) produce complexes of the M(L)₂ type. K₂PdCl₄ (1 mole) reacts with HL¹ and HL² (1 mole) to yield complexes of the general formula PdLCl, the ligands behaving as monobasic tridentates. The electronic spectral and magnetic data show the complexes to be high-spin octahedral, whereas the palladium(II) complexes are diamagnetic square planar. The complexes were characterized by elemental analyses, conductance measurements and i.r. and electronic spectra as well as magnetic susceptibility measurements and thermal (t.g.a. and d.t.a.) analysis.Nuclear Material Authority.     

Complexation of copper(II) with 2′,2′-dialkyl-para-tert-butylbenzohydrazides

The complexation of copper(II) with 2′,2′-dimethyl-, 2′,2′-dibutyl-, and 2′,2′-diisobutyl-para-tert-butylbenzohydrazide in water-ethanol media was studied. The reagents (HL) formed [Cu(HL)]²⁺ and [Cu(HL)₂]²⁺ cationic complexes in a weakly acidic medium and uncharged CuL₂ complexes in an alkaline medium. logK _st was calculated for these complexes. The effect of 2′,2′-alkyl radicals on the stability of the complexes was considered. The obtained results were compared with data on the complexation of copper(II) ions with 2′,2′-dialkylbenzohydrazides.     

Copper(II) and palladium(II) complexes of N,N′-bis(2-hydroxyethyl)stilbenediamine

A new 1,2-diamine ligand, N,N-bis(2-hydroxyethyl)stilbenediamine (L), has been prepared by reduction of the condensation product of benzaldehyde with 2-aminoethanol with Al amalgam. Mononuclear complexes of the [CuL(H₂O)]X₂ type where X=Cl^– or AcO^– with Cu^II and PdLCl₂ with palladium(II) have been prepared and characterized by elemental analysis and i.r., u.v.–vis. or ¹H-n.m.r. spectroscopy.     

Crystal structures ofcatena-[diligatocadmium(II) tetra-μ-cyanocadmate(II)] host clathrates: Diamminecadmium(II) tetracyanocadmate(II)-benzene(1/2), diamminecadmium(II) tetracyanocadmate(II)-aniline(1/2), ethylenediaminecadmium(II) tetracyanocadmate(II)-aniline(1/2), and a novel type bis(aniline)cadmium(II) tetracyanocadmate(II)-aniline(2/1)

The crystal structures of the four title clathrate compounds Cd(NH₃)₂Cd(CN)₄ · 2C₆H₆,I, Cd(NH₃)₂Cd(CN)₄ · 2C₆H₅NH₂,II, Cd(NH₂CH₂CH₂NH₂)Cd(CN)₄ · 2 C₆H₅NH₂,III, and Cd(C₆H₅NH₂)₂Cd(CN)₄ · 0.5C₆H₅NH₂,IV, have been analyzed by single crystal X-ray diffraction methods. CompoundI crystallizes in the monoclinic space groupC2/c,a = 12.063(2),b = 12.174(2),c = 14.621(1) Å,β = 90.976(9)°,Z = 4,R = 0.042 for 2388 reflections;II: monoclinic C₂/c,a = 12.1951(9),b = 12.078(1),c = 14.6921(7) Å,β = 93.436(5)°,Z = 4,R = 0.039 for 2374 reflections;III: monoclinicCc,a = 11.027(1),b = 12.0767(9),c = 15.837(1) Å,β = 92.059(9)°,Z = 4,R = 0.041 for 2883 reflections; andIV: monoclinicP2₁/n,a = 15.169(2),b = 16.019(2),c = 8.866(1) Å,β = 95.73(1)°,Z = 4,R = 0.052 for 3612 reflections. The three-dimensionalcatena-[diamminecadmium(II) tetra-μ-cyanocadmate(II)] hosts ofI andII are substantially isostructural to that of the already known Hofmann-Td-type Cd(NH₃)₂Hg(CN)₄ · 2C₆H₆. The three-dimensional en-Td-typecatena-[catena-μ-ethylenediaminecadmium(II) tetra-μ-cyanocadmate(II)] host ofIII, reinforced by the catena-μ-en linking between the octahedral Cd atoms, accommodates the aniline as the guest with a monoclinic distortion from the tetragonal symmetry of the previously reported en-Td-type benzene clathrate. InIV dual behavior of aniline, one as the unidentate ligand in the three-dimensional host and the other as the guest in the cage-like cavity, has been demonstrated.     

Potentiometric determination of the formation constants for complexes of 3,2′,2″-triaminopropyldiethylamine with cobalt(II), nickel(II), copper(II), zinc(II) and cadmium(II)

The tripodal tetraamine ligand N{(CH₂)₃NH₂}{(CH₂)₂NH₂}₂ (pee), has been investigated as an asymmetrical tetraamine chelating agent for Co^II, Ni^II, Cu^II, Zn^II and Cd^II. The protonation constants for this ligand and the formation constants for its complexes have been determined potentiometrically in 0.1 M KCl at 25 °C. The successive protonation constants (log K _n ) are: 10.22, 9.51, 8.78 and 1.60 (n = 1–4). One complex with formula M(pee)²⁺ (M = Co, Ni, Cu, Zn and Cd) is common to all five metal ions and the formation constant (log _ML) is: 12.15, 14.17, 16.55, 13.35 or 9.74, respectively. In addition to the simple complexes, Co^II, Cu^II and Zn^II also give hydroxo complexes, and Cu^II and Ni^II give complexes with monoprotonated pee. [Zn(pee)](ClO₄)₂ and [Cd(pee)Cl](ClO₄) complexes were isolated and are believed to have tetrahedral and trigonal-bipyramidal structures, respectively.     

Interactions of metal ions with the intermediate of thiamine catalysis: Crystal structures of Cd(II), Hg(II) and Pt(II) complexes of 2-(α-hydroxybenzyl)thiamine

Five complexes of formulae Cd(HBT)X₃·H₂O, Hg₂X₅(HBT) (X=Cl, Br), and Pt(HBT)(NO₂)₃ were prepared by reacting CdX₂, HgX₂ and K₂Pt(NO₂)₄ with 2-(α-hydroxybenzyl)thiamine (HBT), an active intermediate of thiamine catalysis, and their crystal structures were determined by X-ray diffraction. The metal ion binds to the N(1′) site of the pyrimidine ring in each case, despite the different shapes and sizes of metal coordination units; a tetrahedral unit in the cadmium complexes, a double-metal unit consisting of two tetrahedral Hg(II) ions in the mercury complexes and a square-planar unit in the platinum complex. The HBT ligands in these complexes adopt the S conformation, as usually observed in C(2)-substituted derivatives of thiamine, with average torsion angles ϕ_T being ±99° and ϕ_P being ±175°. A ‘two-point’ anion-bridge between the amino group of the pyrimidine ring and the cationic thiazolium ring of the same molecule is found in all the structures, being of the form N(4′α)–H…X₁–M–X₂…thiazolium-ring (M=metal ion), which is one of the factors that affect the S conformation. Stacking interactions between the pyrimidine and phenyl rings play an important role in the molecular conformation and crystal packing. The intramolecular close contact between the oxygen of the C(2)-substituent and the sulfur of the thiazolium ring is also a common feature to these complexes, which gives the mechanistic implications.     

Synthesis,structure and magnetic studies of copper(II)-nickel(II) complexes withN,N′-bis(2-aminopropyl)oxamidocopper(II)

Three novel heterobinuclear complexes have been prepared and identified as [Cu(oxap)Ni(L)₂](ClO₄)₂·ξH₂O, where oxap denotes theN,N′-bis(2-aminopropyl)oxamido dianion and L denotes 2,2′-bipyridine (bipy), 1,10-phenanthroline (phen) or 5-nitro-1,10-phenanthroline (NO₂-phen). The crystal structure of [Cu(oxap)Ni(phen)₂]-(ClO₄)₂·2H₂O has been determined. Crystal data: triclinic, space group , a=12.079 (6), b=12.409 (4), c=17.261 (8) ?, α=70.91 (2), β=86.72 (4), γ=89.19 (3)^o. At room temperature, Z=2. The Cu^II is in a square planar environment and the Ni^II is in an octahedral environment. The Cu−Ni distance is 5.292 ?. The temperature dependences of the magnetic susceptibilities of [Cu(oxap)Ni(phen)₂]-(ClO₄)₂·2H₂O and [Cu(oxap)Ni(bipy)₂](ClO₄)₂ have been studied in the 4.2–300 K range, giving the exchange integral J=−92.4 cm⁻¹ for bipy and J=−94.3 cm⁻¹ for phen. These results are commensurate with antiferromagnetic interactions between the adjacent metal ions.     

4,4′-Bipyridine complexes of molybdenum(II) and tungsten(II)

Treatment of [MI₂(CO)₃(NCMe)₂] with two equivalents of 4,4-bipyridine (4,4-bipy) in CH₂Cl₂ at room temperature gave the MeCN displaced products, [MI₂(CO)₃(4,4-bipy-N)₂] (1) and (2). Equimolar amounts of [MI₂(CO)₃(NCMe)₂] and L (L = PPh₃, AsPh₃ or SbPh₃) react to give [MI₂(CO)₃(NCMe)L], which when reacted in situ with 4,4-bipy yield the new complexes, [MI₂(CO)₃(4,4-bipy-N)L] (3)–(8). Reaction of equimolar quantities of [WI₂(CO)(NCMe)( ²-RC₂R)₂] (R = Me or Ph) and 4,4-bipy gave the new bis(alkyne) complexes, [WI₂(CO)(4,4-bipy-N)( ²-RC₂R)₂] (9) and (10). Treatment of [MI₂(CO)₃(NCMe)₂] with two equivalents of (9) or (10) in CH₂Cl₂ at room temperature affords the bimetallic complexes, [MI₂(CO)₃{WI₂(CO)(4,4-bipy-N,N)( ²-RC₂R)₂}₂] (11)–(14). Equimolar quantities of [MI₂(CO)₃(NCMe)(PPh₃)] (prepared in situ) and (9) or (10), react to give the 4,4-bipy-bridged complexes, [MI₂(CO)₃{WI₂(CO)(4,4-bipy-N,N)( ²-RC₂R)₂}(PPh₃)] (15)–(18). All the new complexes, (1)–(18) were characterised by elemental analysis (C, H and N), i.r. and ¹H-n.m.r. spectroscopy.     

Crystal Structure and Characterization of 2-N-(2-Hydroxy-benzylidene) Furanmethanoamine Nickel(II) Complex

1 INTRODUCTION Recently, the low-spin square-planar nickel(II) complexes and high-spin octahedral nickel(II) complexes with Schiff base ligands have received much attention in optical materials[1～3]. Some nic- kel(II) complexes are widely used as lubricating oil, rubber industry additives, a fire-resistant additive and fungicide for leather[4～7]. Also, their adducts with nitrogen have attracted broad attention due to their potential applications as organic conductors and magnetic mate…     

Copper(II), nickel(II) and palladium(II) complexes of the diamide ligand N,N′-bis(2-carbamoylethyl)ethylenediamine (H2L) and the crystal structure of the carbonyl-oxygen-bonded copper(II) complex [Cu(H2L)](ClO4)2

The preparation of the diamide ligand N,N-bis(2-carbamoylethyl)ethylenediamine (H2L) by Michael addition of ethylenediamine to acrylamide is described. The copper(II) complex [Cu(H2L)](ClO4)2 and the deprotonated complex [CuL]·H2O have been prepared and characterized as has the blue octahedral nickel(II) complex [Ni(H2L)](ClO4)2. The crystal structure of the carbonyl-oxygen-bonded copper(II) complex [Cu(H2L)] (ClO4)2 has been determined (R=5.5%). The stepwise protonation equilibria of the ligand have been studied by potentiometric titration, giving values of logK1= 8.71 and logK2=5.74 at 25°C and I=0.1moldm–3 (NaClO4). The interaction of copper(II) with the ligand (H2L/Cu(II)=1:1) can be fitted to the set of equilibria:With nickel(II), only two complexes, [Ni(H2L)]2+ and [NiL], occur and they have formation constants of log110=7.39 and log 11–2=–11.49. With palladium- (II) the system is similar to that with copper(II) with three complex species, 110, 11–1 and 11–2, with log 110=15.48, log 11–1=11.88 and log 11–2=7.32.     

Complexes of N-aroyl-N′-thiobenzohydrazide with cobalt(II), nickel(II) and zinc(II)

Summary New potential tetradentate ligands, N-benzoyl-N-thiobenzohydrazide (H₂BTBH) and N-salicyl-N-thiobenzohydrazide (H₂SBTH) have been prepared and characterized. Their complexes with Co^II, Ni^II and Zn^II have been prepared and characterized on the basis of elemental analyses, magnetic susceptibility measurements, and u.v.-vis., i.r. and ¹H-n.m.r. spectral studies. The bonding and stereochemistries of the complexes are discussed. H₂BTBH, H₂SBTH and the complexes have been screened towards a number of bacteria.     

Structure of bis-(1,1,1-trifluoro-2-(methylimino)pentanoato-4)copper(II). Thermal properties of N-methylsubstituted copper(II) β-iminoketonates

The single crystal X-ray diffraction (XRD) method was used to determine the structure of the [Cu(mi-tfac)₂] (mi-tfac = MeC(O)CHC(NMe)CF₃) complex at the temperature of 150 K. The crystallographic data are as follows: space group Pnna, a = 11.8798(16) Å, b = 12.0315(16) Å, c = 10.6259(14) Å, V = 1518.8(4) ų, Z = 4, R = 0.0288. The structure is molecular, the coordination environment of copper in the molecule adopts a distorted tetrahedral geometry. The Cu–O and Cu–N distances are 1.9182(13) Å and 1.9610(16) Å respectively, the OCuN chelate angle is 94.18(5)°. The thermal properties of the compounds [Cu(mi-tfac)₂] and [Cu(RC(O)CHC(NMe)R)₂] (R = Me, ^t Bu) in the condensed phase have been studied by the methods of thermogravimetry and differential scanning calorimetry. The thermodynamic characteristics of the melting processes have been determined.     

Synthesis of cobalt(II), nickel(II) and copper(II) complexes with 2-(2-hydroxyphenyliminomethyl)-1-(4-methyl-phenylsulfonamido)benzene and crystal structures of {bis(methanol)[2-(2′-N-tosylaminophenyl)iminomethyl]phenolato}nickel(II) and {bis(2,2′-bipyridine)[2-(2′-N-tosylaminophenyl)iminomethyl]phenolato}copper(II)

Electrochemical oxidation of metal anodes (cobalt, copper and nickel) in acetonitrile solutions of 2-(2-hydroxyphenyliminomethyl)-1-(4-methyl-phenylsulfonamido)benzene (H₂L) gave [CoL], [CuL] and [NiL] complexes. When 1,10-phenanthroline (phen) or 2,2′-bipyridine (bipy) was added to the electrolytic cell, the mixed complexes [MLL′] (M=Co, Cu, L′=bipy or M=Ni, L′=phen) were obtained. A binuclear compound of composition [Ni₂L₂(MeOH)₄] (1) was synthesized by reaction of the ligand H₂L and nickel(II) acetate in methanol. X-ray structure determination showed the compound to be binuclear, with each nickel atom coordinated to two nitrogen and two bridging phenol oxygen atoms of two dianionic ligands and two methanol molecules, in an octahedral environment. The crystal structure of [CuLbipy] (2) was determined by X-ray diffraction; with the copper atom in a distorted bipyramidal environment defined by the two bipyridine nitrogen atoms and by the phenolic oxygen and the nitrogen atoms of the dianionic ligand. The electronic and vibrational spectral data of the complexes are discussed and related to the structure.     

Investigations of Co(II), Ni(II) and Cu(II) (2,2´:6´,2"2"-Terpyridine) Complexes With Sulfur Donor Ligands

The ‘complexes as metal’ strategy has been used to prepare new mixed ligand complexes containing Co(II), Ni(II) and Cu(II) terpyridine (terpy) with dithiooxamide (dto) and thiosemicarbazide (tsc). Characterization of the complexes has been accomplished by elemental analysis, molar conductance, thermal analysis, as well as electronic and IR spectral measurements. It is deduced that the coordination mode of the terpyridine is changed from tridentate in the binary complex to bidentate in the ternary one where the uncoordinated pyridine exists in the protonated form. The dto and tsc act as neutral bidentate ligands coordinating through either sulfur or sulfur and nitrogen atoms respectively, forming chelate ring systems. This revised version was published online in July 2006 with corrections to the Cover Date.     

Synthesis and magnetic properties of heterobinuclear copper(II)–iron(II) complexes with N,N′-bis(2-aminopropyl)oxamidocopper(II)

Six new -oxamido heterobinuclear complexes, namely [Cu(oxap)Fe(L)2]SO4, where oxap denotes the N,N-bis(2-aminopropyl)oxamido dianion and L represents 1,10-phenanthroline (phen); 5-nitro-1,10-phenanthroline (NO2-phen); 5-chloro-1,10-phenanthroline (Cl-phen); 5-methyl-1,10-phenanthroline (Me-phen); 2,2-bipyridine (bpy); and 4,4-dimethyl-2,2-bipyridine (Me2bpy), have been synthesized and characterized by elemental analyses, i.r. spectra, electronic spectra, magnetic moments (at room temperature) and molar conductivity measurements. The temperature dependent magnetic susceptibilities of [Cu(oxap)Fe(bpy)2]SO4 (1) and [Cu(oxap)Fe(phen)2]SO4 (2) have been studied in the 4.2–300K range, giving the exchange integrals J=–20.9cm–1 for (1) and J=–22.5cm–1 for (2). These results are commensurate with antiferromagnetic interactions between adjacent metal ions within each molecule.     

Complexes of N-nicotinoyl-N′-2-furanthiocarbohydrazide with oxovanadium(IV), manganese(II), iron(II & III), cobalt(II), nickel(II), copper(II) and zinc(II)

A new potential tetradentate ligand, N-nicotinoyl-N-2-furanthiocarbohydrazide (H₂Nfth), and its complexes with VO^IV, Mn^II, Fe^II,III, Co^II, Ni^II, Cu^II and Zn^II have been prepared and characterized by elemental analyses, magnetic susceptibility measurements, u.v.–vis, i.r., n.m.r., ES⁺ and FAB mass spectral data. The room temperature e.s.r spectra of the VO^IV and Fe^III complexes yield g values, characteristic of octahedral complexes. The Mössbauer spectra of [Fe(HNfth)₂] and [Fe₂(Nfth)₃] at room temperature and at 78 K suggest the presence of high-spin iron(II) and iron(III), respectively. The complexes are electrically insulating at room temperature, however, their conductivities increase as the temperature increases from 333–383 K, with a band gap of 0.46–0.77 eV, indicating their semiconducting behaviour. H₂Nfth and its soluble complexes have been screened against several bacteria and fungi.     

Investigation of complexes of zinc(II) and cadmium(II)DI-n-butyldithiocarbamates with 2,2′-bipyridyl

A new mixed-ligand complex, Cd(S₂CN(C₄H₉)_{2 2})₂(2,2′-Bipy), was synthesized. A polycrystal X-ray diffraction analysis was performed (DRON-3M and DRON-UM1 diffractometers, CuK_α radiation, Ni filter) and the crystal structure was determined [Enraf-Nonius CAD-4 automatic diffractometer, MoK_α radiation, 2440 nonzero independent reflections, 153 refined structural parameters, R is 0.11 for I>2σ(I)]. Crystal data for C₂₈H₄₄CdN₄S₄ : a = 28.716(4), b = 6.848(6), c = 17.188(2) Å, space group Pcca, V-3380.2(7) ų, Z = 4, M = 679.42, dcaU.= 1.335 g/cm3. The structure consists of monomeric molecules in which the cadmium atom has a distorted octahedral environment. The polycrystal diffraction analysis revealed that the complex is isostructural with the defined complex Zn(S₂CN(C₄Hg)₂)₂(2,2′-Bipy). A crystal-chemical search on metal dialkyldithiocarbamates in the Cambridge Structural Database was accomplished and isostructural pairs of Zn and Cd metal complexes were found.     

Solvatochromism and piezochromism of pentacyanoferrates(II) and of mixed valence iron(II)—iron(III) and ruthenium(II)—ruthenium(III) species

Pressure effects on the MLCT bands of the pyrazine- and 4-cyanopyridine-pentacyanoferrate(II) anions have been established. The relation of these piezochromic effects to the solvatochromism of each complex is put into the correlation between these parameters developed for other d⁶ ternary complexes. The conformance of piezochromic and solvatochromic efrects on MMCT bands for diiron and diruthenium mixed valence complexes to this correlation is examined.