COORDINATION COMPOUNDS OF NICKEL WITH TRITHIOCYANURIC ACID

Abstract

Nickel(II) complexes with a combination of trithiocyanuric acid and diamines or triamines of composition [Ni(aepa)(ttcH)(H₂O)], [Ni(dien)(ttcH)(H₂O)], [Ni(dpta)(ttcH)(H₂O)] H₂O, [Ni(phen)₂(ttcH)]H₂O, [Ni(phen)₃](ttcH)-5H₂O and [Ni(1,2-pn)₃](ttcH)-H₂O (aepa = N-(2-aminoethyl)-1,3-propanediamine,dien = diethylenetriamine,dpta = dipropylenetnamine, phen = 1,10-phenanthroline, 1,2-pn = 1,2-diaminopropane. ttcH₃ = trithiocyanuric acid) have been prepared. The compounds have been characterized by means of elemental analysis, IR and electronic spectroscopies and magnetochemical measurements. Selected complexes were studied by thermal analysis. The compounds can be characterized as distorted octahedral Ni(II) complexes. It was found that the trithiocyanuric dianion can act either as a bidentate ligand or be situated out of the coordination sphere of nickel. The crystal and molecular structure of [Ni(dpta)(ttcH)(H₂O)] H₂O was determined. Crystals are monoclinic, space group P2₁/n, with a = 20.316(4), b = 7.967(2), c = 21.401(4) Å, β = 99.23(3)°, K=3419.1(13)ų, Z = 4, T = 293 K. The nickel(II) atom is six-coordinated by three nitrogen atoms from dipropylene-triamine, nitrogen and sulphur from trithiocyanuric acid, and an oxygen atom from a water molecule in a distorted octahedral geometry.     

Synthesis,characterization and screening of biological activity of Zn(II), Fe(II) and Mn(II) complexes with trithiocyanuric acid

New Zn(II), Fe(II) and Mn(II) complexes with a combination of nitrogen-donor ligands and trithiocyanuric acid (ttcH₃) were prepared and characterized by elemental analysis, IR and UV–Vis spectroscopies. The antitumor activity of the prepared complexes, together with already known Ni(II) species, were assayed in vitro against G-361 (human malignant melanoma), HOS (human osteogenic sarcoma), K-562 (human chronic myelogenous leukaemia) and MCF-7 (human breast adenocarcinoma) tumor cell lines. The IC₅₀ values of the Fe(II) and Mn(II) compounds turned out to be lower than those of cisplatin and oxaliplatin. The antimicrobial activities were evaluated by MIC against bacteria (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Enterococcus faecalis). The molecular structure of [Zn(taa)(ttcH)] · H₂O (taa = tris(2-aminoethyl)amine) was determined by X-ray diffraction. The central atom is pentacoordinated by four N atoms of taa and one N atom of the ttcH dianion.     

Coordination compounds of nickel with trithiocyanuric acid. Part IV. Structure of [Ni(pmdien)(ttcH)] (pmdien = N,N,N′,N′,N′′-pentamethyldiethylenetriamine,ttcH3 = trithiocyanuric acid)

Ni^II mixed-ligand complexes of compositions [Ni(pmdien)(ttcH)] (1), [Ni(baphen)₂(ttcH)] · 4H₂O (2), [Ni-(dpa)(ttcH)(H₂O)] (3), [Ni(cyclam)(ttcH)] · 2H₂O (4), [Ni(hexaa)](ttcH) (5) and [Ni(hexab)(ttcH)] · 2H₂O (6), (baphen = 4,7-diphenyl-1,10-phenanthroline, dpa = 2,2-dipyridylamine, cyclam = 1,4,8,11-tetraazacyclotetradecane, hexaa = 1,3,6,9,11,14-hexaazatricyclo[12.2.1.1^6,9]-octadecane, hexab = 1,8-dimethyl-1,3,6,8,10,13-hexaazacyclotetradecane) have been prepared and characterized by means of i.r., u.v.–vis. spectroscopies and magnetochemical measurements. The redox properties of the complexes were studied by cyclic voltammetry. The crystal and molecular structure of [Ni(pmdien)(ttcH)] was determined. The nickel atom is penta-coordinated by three N atoms of pmdien, and by S and N atoms of trithiocyanurate(2–) anion.     

Phenolate- and acetate (both mu(2)-1,1 and mu(2)-1,3 mode)-bridged face-shared trioctahedral linear Ni(II)(3), Ni(II)(2)M(II) (M = Mn, Co) complexes: ferro- and antiferromagnetic coupling

The complexes [(L)(2)Ni(II)(2)M(II)(mu(2)-1,3-OAc)(2)(mu(2)-1,1-OAc)(2)(S)(2)] x xMeOH [HL = N-methyl-N-(2-hydroxybenzyl)-2-aminoethyl-2-pyridine; M = Ni, S = MeOH, x = 6 (1); M = Mn, S = H(2)O, x = 0 (2); M = Co, S = MeOH, x = 6 (3)] have been synthesized. Crystal structures reveal that three octahedral MII ions form a linear array with two terminal moieties {(L)Ni(II)(mu(2)-1,3-OAc)(mu(2)-1,1-OAc)(MeOH/H(2)O)}(-) in a facial donor set and a central MII ion which is connected to the terminal ions via bridging phenolate and two types of bridging acetates. Magnetic measurements reveal that the Ni(II)(3) and Ni(II)(2)Co(II) centers are ferromagnetically and Ni(II)(2)Mn(II) center is antiferromagnetically coupled. An attempt has been made to rationalize the observed magneto-structural behavior.     

Dinuclear nickel complexes with a Ni(2)O(2) core: a structural and magnetic study

The acetylacetonate complexes [Ni(2)L(1)(acac)(MeOH)] x H(2)O, 1 x H(2)O and [Ni(2)L(3)(acac)(MeOH)] x 1.5H(2)O, 2 x 1.5H(2)O (H(3)L(1) = (2-(2-hydroxyphenyl)-1,3-bis[4-(2-hydroxyphenyl)-3-azabut-3-enyl]-1,3-imidazolidine and H(3)L(3) = (2-(5-bromo-2-hydroxyphenyl)-1,3-bis[4-(5-bromo-2-hydroxyphenyl)-3-azabut-3-enyl]-1,3-imidazolidine) were prepared and fully characterised. Their crystal structures show that they are dinuclear complexes, extended into chains by hydrogen bond interactions. These compounds were used as starting materials for the isolation of the corresponding [Ni(2)HL(x)(o-O(2)CC(6)H(4)CO(2))(H(2)O)] x n MeOH and [Ni(2)HL(x)(O(2)CCH(2)CO(2))(H(2)O)]x nH(2)O dicarboxylate complexes (x = 1, 3; n = 1-3). The crystal structures of [Ni(2)HL(1)(o-O(2)CC(6)H(4)CO(2))(H(2)O)] x MeOH, 3 x MeOH, [Ni(2)HL(3)(o-O(2)CC(6)H(4)CO(2))(H(2)O)] x 3 MeOH, 4 x 3 MeOH and [Ni(2)HL(1)(O(2)CCH(2)CO(2))(H(2)O)] x 2.5H(2)O x 0.25 MeOH x MeCN, 5 x 2.5H(2)O x 0.25 MeOH x MeCN, were solved. Complexes 3-5 show dinuclear [Ni(2)HL(x)(dicarboxylate)(H(2)O)] units, expanded through hydrogen bonds that involve carboxylate and water ligands, as well as solvate molecules. The variable temperature magnetic susceptibilities of all the complexes show an intramolecular ferromagnetic coupling between the Ni(II) ions, which is attempted to be rationalized by comparison with previous results and in the light of molecular orbital treatment. Magnetisation measurements are in accord with a S = 2 ground state in all cases.     

Synthesis and Crystal Structure of an Ion-pair Compound: [H_2(teta)]~(2+)·[Ni(CN)_4]~(2-)·2H_2O (teta = Meso-5,7,7,12,14,14-hexamethyl- 1,4,8,11-tetraazacyclotetradecane)

1INTRODUCTION The macrocyclic compounds play an important ro-le in life science and materials science[1].In recent years,teta has gained extensive attention as a raw material of crystal engineering,and its coordination behavior with metallic ion has been …     

Molecular-programmed self-assembly of homo- and heterometallic penta- and hexanuclear coordination compounds: synthesis, crystal structures, and magnetic properties of ladder-type CuII2MIIx (M=Cu, Ni; x=3, 4) oxamato complexes with CuII2 metallacyclophane cores

New homo- and heterometallic, hexa- and pentanuclear complexes of formula {[Cu2(mpba)2(H2O)F][Cu(Me5dien)]4}(PF6)(3).5H2O (1), {[Cu2(Me3mpba)2(H2O)2][Cu(Me5dien)]4}(ClO4)(4).12H2O (2), {[Cu2(ppba)2][Cu(Me5dien)]4}(ClO4)4 (3), and [Ni(cyclam)]{[Cu2(mpba)2][Ni(cyclam)]3}(ClO4)(4).6H2O (4) [mpba=1,3-phenylenebis(oxamate), Me3mpba=2,4,6-trimethyl-1,3-phenylenebis(oxamate), ppba=1,4-phenylenebis(oxamate), Me5dien=N,N,N'N' ',N' '-pentamethyldiethylenetriamine, and cyclam=1,4,8,11-tetraazacyclotetradecane] have been synthesized through the use of the "complex-as-ligand/complex-as-metal" strategy. The structures of 1-3 consist of cationic CuII6 entities with an overall [2x2] ladder-type architecture which is made up of two oxamato-bridged CuII3 linear units connected through two m- or p-phenylenediamidate bridges between the two central copper atoms to give a binuclear metallacyclic core of the cyclophane-type. Complex 4 consists of cationic CuII2NiII3 entities with an incomplete [2x2] ladder-type architecture which is made up of oxamato-bridged CuIINiII and CuIINiII2 linear units connected through two m-phenylenediamidate bridges between the two copper atoms to give a binuclear metallacyclophane core. The magnetic properties of 1-3 and 4 have been interpreted according to their distinct "dimer-of-trimers" and "dimer-plus-trimer" structures, respectively, (H=-J(S1A.S3A+S1A.S4A+S2B.S5B+S2B.S6B)-J'S1A.S2B). Complexes 1-4 exhibit moderate to strong antiferromagnetic coupling through the oxamate bridges (-JCu-Cu=81.3-105.9 cm-1; -JCu-Ni=111.6 cm-1) in the trinuclear and/or binuclear units. Within the binuclear metallacyclophane core, a weak to moderate ferromagnetic coupling (J'Cu-Cu=1.7-9.0 cm-1) operates through the double m-phenylenediamidate bridge, while a strong antiferromagnetic coupling (J'Cu-Cu=-120.6 cm-1) is mediated by the double p-phenylenediamidate bridge.     

Conversion of d-penicillaminato trinuclear to mononuclear palladium(ii) structure by diamine ligands: remarkable enantioselectivity toward racemic 1,2-cyclohexanediamine

The reactions of an S-bridged trinuclear palladium(ii) complex, [Pd(3)(d-pen-N,O,S)(3)] (d-H(2)pen = d-penicillamine), with ethylenediamine (en) and racemic (R,R/S,S) 1,2-cyclohexanediamine (chxn) in water gave mononuclear palladium(ii) complexes, [Pd(d-pen-N,S)(en)] (1) and [Pd(d-pen-N,S)(chxn)] (2), respectively. Of two diastereomers, [Pd(d-pen-N,S)(R,R-chxn)] (2(R)) and [Pd(d-pen-N,S)(S,S-chxn)] (2(S)), possible for 2, 2(S) was exclusively isolated in a high yield.     

Mixed fluoroamine complexes of chromium(III)

Summary Mixed difluoro(diamine)(diamme)chromium(III) complexes have been synthesized with ethylenediamine (en), 1,3 propanediamine(tn) and 1,2-cyclohexanediamine(chxn):trans-[CrF₂(aa)(bb)]Br (aa=en, bb=tn; aa=tn, bb= chxn) andcis-[CrF₂(aa)(bb)]Br (aa=en, bb=chxn). The corresponding fluoroaqua(diamine) (diamine)chromium(III) complexes have been prepared by acid hydrolysis as perchlorate or iodide salts. All have been characterized by chemical analysis, electronic and i.r. spectra and conductivity measurements.     

Intramolecular hydrogen bonding controls 1,3-N,S- vs. 1,5-S,S'-coordination in Ni(II) complexes of N-thiophosphorylated thioureas RNHC(S)NHP(S)(OiPr)2

Reaction of the deprotonated N-thiophosphorylated thioureas RNHC(S)NHP(S)(OiPr)(2) (R = Ph, HL(I); 2-MeC(6)H(4)-, HL(II); 2,6-Me(2)C(6)H(3)-, HL(III); 2,4,6-Me(3)C(6)H(2)-, HL(IV); Me-, HL(V)) with Ni(II) leads to complexes of the formula [NiL(I-V)(2)]. The molecular structures of the thioureas HL(II-V) and the complexes [NiL(II-V)(2)] in the solid were elucidated by single-crystal X-ray diffraction analysis. In the complexes, the metal is found to be in a square planar trans-N(2)S(2) ([NiL(II-IV)(2)]) environment formed by the C=S sulfur atoms and the P-N nitrogen atoms, or in a square planar trans-S(2)S'(2) ([NiL(V)(2)]) environment formed by the C=S and P=S sulfur atoms of two deprotonated ligands. DFT calculations confirmed that the [Ni(L(II-IV)-N,S)(2)] isomers are more stable (by 16-21 kcal mol(-1)) than the corresponding [Ni(L(II-IV)-S,S')(2)] conformers. The main reason for higher stability of the 1,3-N,S vs. 1,5-S,S' isomers is the formation of intramolecular N-H···S=P hydrogen bonds. In solution the complexes [Ni(L(II-V)-N,S)(2)] have an exclusive 1,3-N,S coordination, while the compound [Ni(L(I)-N,S)(2)] exhibits two isomers in the (1)H and (31)P NMR spectra. The major species is assigned to the 1,3-N,S coordinated isomer, while the minor (～25%) signals are due to the 1,5-S,S' isomer. UV-Vis spectroscopic results are in line with this. The electrochemical measurements reveal reversible one-electron reduction and irreversible oxidations, both assigned to ligand-centred processes.     

Solvothermal synthesis and characterization of a series of lanthanide thiostannates(IV): the first examples of inorganic-organic hybrid cationic lanthanide thiostannates(IV)

A series of new lanthanide thiostannates(IV), [Y(2)(dien)(4)(μ-OH)(2)]Sn(2)S(6) (1, dien = diethyl-enetriamine), (tetaH)(2)[Ln(2)(teta)(2)(tren)(2)(μ-Sn(2)S(6))]Sn(2)S(6) [Ln = Eu (2), Sm (3); teta = triethylenetetramine; tren = tris(2-aminoethyl)amine] and [Eu(2)(tepa)(2)(μ-OH)(2)(μ-Sn(2)S(6))](tepa)(0.5)·H(2)O (4, tepa = tetraethylene-pentamine) were solvothermally synthesized and structurally characterized. 1 consists of a binuclear [Y(2)(dien)(4)(μ(2)-OH)(2)](4+) cation and a discrete dimeric [Sn(2)S(6)](4-) anion. Both 2 and 3 are isostructural and composed of [Ln(2)(teta)(2)(tren)(2)(μ-Sn(2)S(6))](2+) cations, protonated triethylenetetramines (tetaH), and discrete dimeric [Sn(2)S(6)](4-) anions. A Sn(2)S(6)(4-) anion bridges two [Ln(teta)(tren)](3+) cations via the trans-S(t) (t = terminal) atoms to form the first examples of inorganic-organic hybrid thiostannate cations [Ln(2)(teta)(2)(tren)(2)(μ-Sn(2)S(6))](2+). 4 consists of one-dimensional (1-D) neutral chains [Eu(2)(tepa)(2)(μ-OH)(2)(μ-Sn(2)S(6))](n) built up from the linkage of dinuclear complex cations [Eu(2)(tepa)(2)(μ(2)-OH)(2)](4+) and bridging anions [Sn(2)S(6)](4-), free tepa molecules, and lattice water molecules. The present compounds exhibit wide-band gap semiconducting properties with absorption band edges between 2.40 and 2.91 eV.     

Syntheses, structures, and electrochemical properties of platinum(II) complexes containing di-tert-butylbipyridine and crown ether annelated dithiolate ligands

A series of new platinum(II) complexes containing both 4,4'-di-tert-butyl-2,2'-bipyridine (dbbpy) and the extended tetrathiafulvalenedithiolate ligands have been prepared and characterized. These complexes include [Pt(dbbpy)(C8H4S8)] (1; C8H4S82- = 2-{(4,5-ethylenedithio)-1,3-dithiol-2-ylidene}-1,3-dithiol-4,5-dithiolate), [Pt(dbbpy)(ptdt)] (2; ptdt = 2-{(4,5-cyclopentodithio)-1,3-dithiol-2-ylidene}-1,3-dithiol-4,5-dithiolate), [Pt(dbbpy)(mtdt)] (3; mtdt = 2-{(4,5-methylethylenedithio)-1,3-dithiol-2-ylidene}-1,3-dithiol-4,5-dithiolate), [Pt(dbbpy)(btdt)] (4; btdt = benzotetrathiafulvalenedithiolate), [Pt(dbbpy)(C8H6S8)] (5; C8H6S82- = 2-{4,5-bis(methylthio)-1,3-dithiol-2-ylidene}-1,3-dithiol-4,5-dithiolate), [Pt(dbbpy)(3O-C6S8)] (6; 3O-C6S82- = 2-{4,5-dithia-(3',6',9'-trioxaundecyl)-1,3-dithiol-2-ylidene}-1,3-dithiol-4,5-dithiolate), and [Pt(dbbpy)(4O-C6S8)] (7; 4O-C6S82- = 2-{4,5-dithia-(3',6',9',12'-tetraoxatetradecyl)-1,3-dithiol-2-ylidene}-1,3-dithiol-4,5-dithiolate). The crystal structures of a new ligand precursor (2-[4,5-dithia-(3',6',9',12'-tetraoxatetradecyl)-1,3-dithiol-2-ylidene]-4,5-bis(2-cyanoethylsulfanyl)-1,3-dithiole, IIIc) and complexes 5-7 have been determined by X-ray crystallography. Complexes 1-7 show intense electronic absorption bands in the UV-vis region due to the intramolecular mixed metal/ligand-to-ligand charge-transfer transition, and they display significant solvatochromic behavior. Redox properties of these compounds have been investigated by cyclic voltammetry, and complex 7 shows a significant response for Na+ ions with a large positive shift of ca. 45 mV.     

Heterocyclic nickel(II) dithiocarbamates with aromatic thiols as bridging ligands

Binuclear NiII dithiocarbamates, with aromatic monothiols as bridging ligands, of composition [Ni(-L) (Rdtc)]2 [dtc = S2CN, R = C4H8O (morph), C5H10 (pip), C4H8 (pld); HL = thiophenol, 4-methylthiophenol or 2-thionaphthol] and [Ni(-L)(HR1dtc)]2 {R1 = C11H11N2O (aap)} have been prepared and characterized by elemental analyses, i.r. and electron spectroscopy, magnetochemical and conductivity measurements, and thermal analysis. The methods used indicate that the complexes are diamagnetic, complex non-electrolytes with two square-planar NiS4 chromophores.     

Mixed phosphine and group-13 metal ligator complexes [(PR3)(a)M(ECp*)b] (M = Mo, Ni; E = Ga, Al; R = C6H5, cyclo-C6H11, CH3)

Treatment of [Mo(N(2))(PMe(3))(5)] with two equivalents GaCp* (Cp* = η(5)-C(5)(CH(3))(5)) leads to the formation of cis-[Mo(GaCp*)(2)(PMe(3))(4)] (1), while AlCp* did not react with this precursor. In addition, [Ni(GaCp*)(2)(PPh(3))(2)] (2a), [Ni(AlCp*)(2)(PPh(3))(2)] (2b), [Ni(GaCp*)(2)(PCy(3))(2)] (3a), [Ni(GaCp*)(2)(PMe(3))(2)] (3b), [Ni(GaCp*)(3)(PCy(3))] (4) and [Ni(GaCp*)(PMe(3))(3)] (5) have been prepared in high yields by a direct synthesis from [Ni(COD)(2)] and stoichiometric amounts of the ligands PR(3) and ECp* (E = Al, Ga), respectively. All compounds have been fully characterized by (1)H, (13)C, and (31)P NMR spectroscopy, elemental analysis and single crystal X-ray diffraction studies.     

Pt(0) and Pd(0) olefin complexes of the metalloid N-heterocyclic carbene analogues [E(I)(ddp)] (ddp=2-{(2,6-diisopropylphenyl)amino}-4-{(2,6-diisopropylphenyl)imino}-2-pentene; E=Al, Ga): ligand substitution, H--H and Si--H bond activation, and cluster formation

Various products of the reaction of [E(ddp)] (ddp=2-{(2,6-diisopropylphenyl)amino}-4-{(2,6-diisopropylphenyl)imino}-2-pentene; E=Al, Ga) with Pt(0) and Pd(0) olefin complexes are reported. Thus, the reaction of [Pt(cod)(2)] (cod=1,5-cyclooctadiene) with two equivalents of [Ga(ddp)] yields [Pt(1,3-cod){Ga(ddp)}(2)] (1), whereas treatment of [Pd(2)(dvds)(3)] (dvds=1,1,3,3-tetramethyl1,3-divinyldisiloxane) with [E(ddp)] leads to the monomeric compounds [(dvds)Pd{E(ddp)}] (E=Ga (2 a), Al (2 b)) by substitution of the bridging dvds ligand. Both 1 and 2 a readily react with strong pi-acceptor ligands such as CO or tBuNC to give the dimeric compounds [M{mu(2)-Ga(ddp)}(L)] (L=CO, tBuNC; M=Pt (3 a, 5 a), Pd (3 b, 5 b)), respectively. Based on (1)H NMR spectroscopic data, [Pt{Ga(ddp)}(2)(CO)] is likely to be an intermediate in the formation of 3 a. Furthermore, reactions of 1 with H(2) and HSiEt(3) yield the monomeric compounds [Pt{Ga(ddp)}(2)(H)(2)] (7) and [Pt{Ga(ddp)}(2)(H)(SiEt(3))] (8). Finally, the reaction of [Pt(cod)(2)] with one equivalent of [Ga(ddp)] in the presence of H(2) in hexane gives the new dimeric cluster [Pt{mu(2)-Ga(ddp)}(H)(2)](2) (9).     

Indium-sulfur supertetrahedral polymers integrated with [M(phen)3]2+ cations (M = Ni and Fe)

A series of supertetrahedral polymers of chalcogenometalates (T3 cluster compounds) integrated with M-phen complexes (phen =1,10-phenanthroline; M = Ni, Fe) was prepared by a similar solvothermal technique. Compound [Fe(phen)(3)](4)[H(4)In(20)S(38)]·Hphen·3HDMA·8H(2)O (Mp-InS-4) (DMA = dimethylamine) is a 1-D straight chain. Compounds [M(phen)(3)](4)[In(20)S(37)]·6Hphen·4H(2)O (M = Ni, Mp-InS-5; Fe, Mp-InS-6) are the first reported 2-D Tn polymers integrated with complex cations of [M(phen)(3)](2+). Compound [Ni(phen)(3)](4)[H(4)In(20)S(38)]·2Hphen·2HDMA·3H(2)O (Mp-InS-7) shows a zigzag 1-D structure. We find that the reaction time is an important factor in assembling of the T3 clusters. Prolonging the reaction time seems favorable to the higher condensed phases (from 0-D to 2-D). However, a longer reaction time resulted in the crack of 2-D structure. Integrating M-phen complex cations with the chalcogenido anions can improve absorption of the materials in the visible range due to the charge transfers within the cations or between cations and anions.     

Synthesis and Crystal Structure of an Ion-pair Compound:[H2(teta)]2+·[Ni(CN)4]2-·2H2O(teta=Meso-5,7,7,12,14,14-hexamethyl- 1,4,8,11-tetraazacyclotetradecane)

The ion-pair compound [H2(teta)]2+·[Ni(CN)4] 2-·2H2O (C20H42N8NiO2, teta = meso- 5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane) was synthesized and characterized by single-crystal X-ray diffraction. The crystal belongs to monoclinic, space group P21/n with a = 10.0784(10), b = 9.5411(7), c = 14.1010(14)(A), β= 106.752(2)o, V = 1298.4(2) (A)3, Mr = 485.33, Z = 2, Dc = 1.241 g/cm3,μ(MoKα) = 0.778 mm-1 and F(000) = 524. The structure was refined to R = 0.0391 and wR = 0.0870 for 2614 observed reflections with I > 2σ(I). The title compound contains one [Ni(CN)4]2- anion, one protonated macrocyclic tetraamine cation [H2(teta)]2+ and two water molecules. There are multiform hydrogen bonds in the compound to link the different components and stabilize the crystal structure.     

Influence of the coordination mode in [Ni{RC(S)NP(S)(OiPr)2}2] for the formation of nickel-containing nanoparticles

The complex [Ni{2-PyNHC(S)NP(S)(OiPr)(2)-1,5,7-N,N',S}(2)] ([NiL(I)(2)]) dissolved in tri-n-octylphosphine (TOP) is decomposed in hot hexadecylamine (HDA) to give TOP-capped Ni nanoparticles. The same procedure using [Ni{2-MeC(6)H(4)NHC(S)NP(S)(OiPr)(2)}(2)-1,3-N,S] ([NiL(II)(2)]) and [Ni{PhC(S)NP(S)(OiPr)(2)-1,5-S,S'}(2)] ([NiL(III)(2)]) leads to the formation of NiS nanoparticles with the rhombohedral and hexagonal structures, respectively. NiH(x) nanoparticles were also produced from a mixture of [NiL(I)(2)] and N(2)H(4). The obtained Ni nanoparticles can be used for the catalytic addition of Ph(2)S(2) to 1-, 2- and 3-hexynes.     

Mononuclear nickel(III) complexes [Ni(III)(OR)(P(C6H3-3-SiMe3-2-S)3)](-) (R = Me, Ph) containing the terminal alkoxide ligand: relevance to the nickel site of oxidized-form [NiFe] hydrogenases

The unprecedented nickel(III) thiolate [Ni (III)(OR)(P(C 6H 3-3-SiMe 3-2-S) 3)] (-) [R = Ph ( 1), Me ( 3)] containing the terminal Ni (III)-OR bond, characterized by UV-vis, electron paramagnetic resonance, cyclic voltammetry, and single-crystal X-ray diffraction, were isolated from the reaction of [Ni (III)(Cl)(P(C 6H 3-3-SiMe 3-2-S) 3)] (-) with 3 equiv of [Na][OPh] in tetrahydrofuran (THF)-CH 3CN and the reaction of complex 1 with 1 equiv of [Bu 4N][OMe] in THF-CH 3OH, respectively. Interestingly, the addition of complex 1 into the THF-CH 3OH solution of [Me 4N][OH] also yielded complex 3. In contrast to the inertness of complex [Ni (III)(Cl)(P(C 6H 3-3-SiMe 3-2-S) 3)] (-) toward 1 equiv of [Na][OPh], the addition of 1 equiv of [Na][OMe] into a THF-CH 3CN solution of [Ni (III)(Cl)(P(C 6H 3-3-SiMe 3-2-S) 3)] (-) yielded the known [Ni (III)(CH 2CN)(P(C 6H 3-3-SiMe 3-2-S) 3)] (-) ( 4). At 77 K, complexes 1 and 3 exhibit a rhombic signal with g values of 2.31, 2.09, and 2.00 and of 2.28, 2.04, and 2.00, respectively, the characteristic g values of the known trigonal-bipyramidal Ni (III) [Ni (III)(L)(P(C 6H 3-3-SiMe 3-2-S) 3)] (-) (L = SePh, SEt, Cl) complexes. Compared to complexes [Ni (III)(EPh)(P(C 6H 3-3-SiMe 3-2-S) 3)] (-) [E = S ( 2), Se] dominated by one intense absorption band at 592 and 590 nm, respectively, the electronic spectrum of complex 1 coordinated by the less electron-donating phenoxide ligand displays a red shift to 603 nm. In a comparison of the Ni (III)-OMe bond length of 1.885(2) A found in complex 3, the longer Ni (III)-OPh bond distance of 1.910(3) A found in complex 1 may be attributed to the absence of sigma and pi donation from the [OPh]-coordinated ligand to the Ni (III) center.     

Synthesis, structure, and reactivity of dinuclear nickel amino-thiophenolate complexes bearing bridging VO2(OH)2- and VO2(OR)2- coligands

A series of novel mixed ligand dinickel complexes of the type [Ni(II)(2)L(μ-L')](+), where L' is a tetrahedral oxo-alkoxo vanadate (L' = [O(2)V(V)(OR)(2)](-), R = H or alkyl) and L a macrocyclic N(6)S(2) supporting ligand, have been prepared, and their esterification reactivity has been studied. The orthovanadate complex [Ni(2)L(μ-O(2)V(OH)(2))](+) (2), prepared by reaction between [Ni(2)L(μ-Cl)]ClO(4) with Na(3)VO(4) and a phase transfer reagent in CH(3)CN, reacts smoothly with MeOH and EtOH forming the vanadate diesters [Ni(2)L(μ-O(2)V(OMe)(2))](+) (3) and [Ni(2)L(μ-O(2)V(OEt)(2))](+) (4). The dialkyl orthovanadate esters in 3 and 4 are readily transesterified with mono- and difunctional alcohols. Complex 3 can also be generated from 4 by transesterification with MeOH. Complexes 3 and 4 react with diols (ethylene glycol, propylene glycol and diethylene glycol) as well to afford the complexes [Ni(2)L(μ-O(2)V(OH)(OCH(2)CH(2)OH))](+) (5), [Ni(2)L(μ-O(2)V(OCH(2))(2)CH(2))](+) (6), and [Ni(2)L(μ-O(2)V(OCH(2)CH(2))(2)O)] (7). The crystal structures of the tetraphenylborate salts of complexes 3-7 reveal in each case four-coordinate O(2)V(V)(OR)(2)(-) groups bonded in a μ(1,3)-bridging mode to generate trinuclear complexes with a central N(3)Ni(μ-S)(2)(μ(1,3)-O(2)V(OR)(2))NiN(3) core. The stabilization of the four-coordinate V(V)O(2)(OR)(2)(-) moieties is a consequence of both the two-point coordinative fixation to and the steric protection of the bowl-shape binding pocket of the [Ni(2)L](2+) fragment. Cyclic voltammetry experiments reveal that the encapsulated vanadate esters are not reduced in a potential window of -2.0 to +2.5 V vs SCE. The spins of the nickel(II) (S(i) = 1 ions) in 3 are weakly ferromagnetically coupled (J = +23 cm(-1), (H = -2JS(1)S(2))) to produce an S = 2 ground state.