Metal derivatives of thiosemicarbazones: crystal structure of [chloro bis(triphenylphosphino) (thiophene-2-carbaldehyde thiosemicarbazone) copper(I)] complex

Reactions of copper(I) halides (X = Cl, Br, I) with thiophene-2-carbaldehyde thiosemicarbazone and triphenylphosphine in 1 : 1 : 2 molar ratio yield tetrahedral mononuclear complexes, [CuX(η¹-S-Httsc)(Ph₃P)₂] (X = Cl, 1; Br, 2; I, 3), characterized by elemental analysis, IR, NMR (¹H, ¹³C, ³¹P), and single crystal X-ray crystallography (1). The unit cell of 1 has two independent distorted tetrahedral molecules (1a and 1b) with different bond parameters. One acetonitrile is entrapped between them. Crystal data: C₈₆H₇₇Cl₂Cu₂N₇P₄S₄ 1: triclinic, P-1, a = 12.8810(9), b = 18.5049(13), c = 18.7430(13) Å, α = 63.7130(10), β = 89.0960(10), γ = 85.5010(10)°, V = 3992.4(5) ų, Z = 2, R _(int) = 0.0314. Bond parameters: 1a, Cu(1A)–Cl(1A), 2.3803(5); Cu(1A)–S(1A), 2.3822(5); Cu(1A)–P(1A), 2.2498(5) Å; P(1A)–Cu(1A)–P(2A), 124.294(19)°; 1b, Cu(1B)–Cl(1B), 2.3975(5); Cu(1B)–S(1B), 2.3756(5); Cu(1B)–P(1B), 2.2777(5) Å; P(1B)–Cu(1B)–P(2B), 127.156(19)°.     

Crystal structures of 3/4-pyridyl-based thiosemicarbazones and related Cu and Ni coordination compounds

In this investigation, the crystal structures of the thio-ligands 3-formylpyridine 4-phenylthiosemicarbazone (C₁₃H₁₂N₄S, 1 ) and 4-benzoylpyridine 4-ethylthiosemicarbazone (C₁₅H₁₆N₄S, 2 ), and of two new coordination compounds, chlorido(3-formylpyridine 4-phenylthiosemicarbazone-κS)bis(triphenylphosphane-κP)copper(I) acetonitrile monosolvate, [CuCl(C₁₃H₁₂N₄S)(C₁₈H₁₅P)₂]·CH₃CN, 3 , and bis(3-formylpyridine 4-ethylthiosemicarbazonato-κ²N¹,S)nickel(II), [Ni(C₉H₁₁N₄S)₂], 4 , are reported. In complex 3 , the thio-ligand coordinates in a neutral form to the Cu atom through its S-donor atom, and in complex 4 , the anionic thio-ligand chelates to the Ni atom through N- and S-donor atoms. The geometry of complex 3 is distorted tetrahedral [bond angles 99.70 (5)–123.23 (5)°], with the P—Cu—P bond angle being the largest, while that of complex 4 is square planar, with trans-S—Ni—S and N—Ni—N bond angles of 180°.     

The Influence of Substituents at C2 Carbon Atom of Thiosemicarbazones {R(H)C2=N3‐N2(H)‐C1(=S)‐N1H2} on their Dentacy in PtII/PdII Complexes: Synthesis,Spectroscopy, and Crystal Structures

The coordination chemistry of platinum(II) with a series of thiosemicarbazones {R(H)C²=N³‐N²(H)‐C¹(=S)‐N¹H₂, R = 2‐hydroxyphenyl, H₂stsc; pyrrole, H₂ptsc; phenyl, Hbtsc} is described. Reactions of trans‐PtCl₂(PPh₃)₂ precursor with H₂stsc (or H₂ptsc) in 1 : 1 molar ratio in the presence of Et₃N base yielded complexes, [Pt(η³‐ O, N³, S‐stsc)(PPh₃)] ( 1 ) and [Pt(η³‐ N⁴, N³, S‐ptsc)(PPh₃)] ( 2 ), respectively. Further, trans‐PtCl₂(PPh₃)₂ and Hbtsc in 1 : 2 (M : L) molar ratio yielded a different compound, [Pt(η²‐ N³, S‐btsc)(η¹‐S‐btsc)(PPh₃)] ( 3 ). Complex 1 involved deprotonation of hydrazinic (‐N²H‐) and hydroxyl (‐OH) groups, and stsc^2? is coordinating via O, N³, S donor atoms, while complex 2 involved deprotonation of hydrazinic (‐N²H‐) and ‐N⁴H groups and ptsc^2? is probably coordinating via N⁴, N³, S donor atoms. Reaction of PdCl₂(PPh₃)₂ with Hbtsc‐Me {C₆H₅(CH₃)C²=N³‐N²(H)‐C¹(=S)‐N¹H₂} yielded a cyclometallated complex [Pd(η³‐C, N³, S‐btsc‐Me)(PPh₃)] ( 4 ). These complexes have been characterized with the help of analytical data, spectroscopic techniques {IR, NMR (¹H, ³¹P), U.V} and single crystal X‐ray crystallography ( 1 , 3 and 4 ). The effects of substituents at C² carbon of thiosemicarbazones on their dentacy and cyclometallation are emphasized.     

Metal Derivatives of Heterocyclic Thioamides: Synthesis and Crystal Structures of Copper Complexes with 1‐Methyl‐1,3‐imidazoline‐2‐thione and 1,3‐Imidazoline‐2‐thione

Reactions of copper(I) halides (Cl, Br, I) with 1‐methyl‐1, 3‐imidazoline‐2‐thione (mimzSH) in 1 : 2 molar ratio yielded sulfur‐bridged dinuclear [Cu₂X₂(μ‐S‐mimzSH)₂(η¹‐S‐mimzSH)₂] (X = I, 1 , Br, 2 ; Cl, 3 ) complexes. Copper(I) iodide with 1,3‐imidazoline‐2‐thione (imzSH₂) and Ph₃P in 1 : 1 : 1 molar ratio has also formed a sulfur‐bridged dinuclear [Cu₂I₂(μ‐S‐imzSH₂)₂(PPh₃)₂] ( 4 ) complex. The central Cu(μ‐S)₂Cu cores form parallelograms with unequal Cu–S bond distances {2.324(2), 2.454(3) Å} ( 1 ); {2.3118(6), 2.5098(6) Å} ( 2 ); {2.3075(4), 2.5218(4) Å} ( 3 ); {2.3711(8), 2.4473(8) Å} ( 4 ). The Cu···Cu separations, 2.759–2.877Å in complexes 1 – 3 are much shorter than 3.3446Å in complex 4 . The weak intermolecular interactions {H₂CH···S^# ( 2 ); CH···Cl^# ( 3 ); NH···I^# ( 4 )} between dimeric units in complexes 2 – 4 lead to the formation of linear 1D polymers.     

Coinage (Cu,Ag) metal derivatives of salicylaldehyde N-ethylthiosemicarbazone: synthesis,spectroscopy, and structures

Reactions of copper(I) halides with triphenyl phosphine in acetonitrile followed by the addition of salicylaldehyde N-ethylthiosemicarbazone {(2-OH–C₆H₄)(H)C²=N³–N²H–C¹(=S)N¹HEt, H₂stsc-NEt} in chloroform in 1?:?2?:?1 (Cl) or 1?:?1?:?1 (Br, I) molar ratios yield mononuclear, [CuCl(η ¹-S-H₂stsc-NHEt)(PPh₃)₂] (1) and sulfur-bridged dinuclear, [Cu₂X₂(μ-S-H₂stsc-NEt)₂(PPh₃)₂] (X?=?Br, 4; I, 5) complexes. Similarly, reaction of silver halides (Cl, Br) with H₂stsc-NEt in acetonitrile followed by the addition of PPh₃ to the solid that formed (1?:?1?:?2 molar ratio), yielding mononuclear complexes, [AgX(η ¹-S-H₂stsc-NHEt)(PPh₃)₂] (Cl, 2; Br, 3). All these complexes are characterized with analytical data, IR, and NMR spectroscopy and single-crystal X-ray crystallography. The ligand favored η ¹-S bonding in 1, 2, and 3, and μ-S bonding in 4 and 5. Cu?···?Cu contacts were 3.063?Å. The complexes form 1-D or 2-D H-bonded networks, entrapping solvent in some cases.     

COPPER(I) COMPLEXES WITH N-(P-NITROPHENYL)-N′-ALKOXYCARBONYLTHIOUREA: SYNTHESES AND CRYSTAL STRUCTURES OF [Cu(H2net)2CI] · CH2CI2 AND [Cu(H2nmt)2CI]2·(CHCI3)2

Abstract

Two copper(I) complexes, [Cu(H₂net)₂Cl] · CH₂Cl₂ (1) and [Cu(H₂nmt)₂Cl]₂ · (CHCl₃)₂ (2), were synthesized by the reaction of CuCl₂ · 2H₂O with N-(p-nitrophenyl)-N′-(ethoxycarbonyl)-thiourea (H₂net) and N-(p-nitrophenyl)-N′-(methoxycarbonyl)-thiourea(H₂nmt), respectively. Both complexes crystallize in the monoclinic space group C2/c. For complex 1, a = 29.52(2), b=13.920(6), c = 14.873(3)Å; β= 101.75(2)°, V = 5984(4) ų, Z = 8 and R = 0.053; for complex 2, a = 30.68(1), b = 13.369(4), c = 14.226(7) Å, β = 99.52(4)°. V = 5754(4) ų, Z = 4 and R = 0.063. In complex 1, two H₂net molecules are bonded to Cu(I) atom through two S atoms forming a mononuclear complex with trigonal geometry for the Cu(I) ion [Cl(1)-Cu-S(1)=118.54(7), Cl(1)-Cu-S(2)=119.70(7), S(1)-Cu-S(2)=112.17(8)°, Cu-S(1) = 2.251(2), Cu-S(2) = 2.255(2), Cu-Cl(1) = 2.263(2) Å]. Complex 2 is a dimer formed by long Cu-S interactions [Cu-S* = 2.607(3) Å] from adjacent twc H₂nmt molecules; the Cu(I) ion has distorted tetrahedral coordination [Cl(1)-Cu-S(1) = 119.8(1), Cl(1)-Cu-S(2)=120.0(1), S(1)-Cu-S(2)=108.85(9)°] with unequal Cu-S [2.268(2), 2.247(2)Å] and Cu-Cl(1) [2.255(2)Å] bonds.     

Dinuclear copper(II) complex and 1-D copper(II) complex with taurine Schiff base: synthesis,crystal structure,and properties

A dinuclear copper(II) compound, [Cu(btssb)(H₂O)]₂ · 4(H₂O) (1), and a 1-D chain copper(II) compound, [Cu(ctssb)(H₂O)] _n (2) [where H₂btssb is 2-[(5-bromo-2-hydroxy-benzylidene)-amino]-ethanesulfonic acid and H₂ctssb is 2-[(3,5-dichloro-2-hydroxy-benzylidene)-amino]-ethanesulfonic acid], were prepared and characterized. Compound 1 crystallizes in the monoclinic space group P2₁/c, with a = 10.109(2) Å, b = 20.473(4) Å, c = 6.803(1) Å, β = 100.32(3)°, V = 1385.1(5) ų, and Z = 2; R ₁ for 1796 observed reflections [I > 2σ(I)] was 0.0357. The geometry around each copper(II) can be described as slightly distorted square pyramidal. The Cu^II ··· Cu^II distance is 5.471(1) Å. Compound 1 formed a 1-D network through O–H ··· O hydrogen bonds and 1-D water chains exist. The 1-D chain complex 2 crystallizes in the triclinic space group P 1, with a = 5.030(2) Å, b = 7.725(2) Å, c = 17.011(5) Å, α = 92.706(4)°, β = 97.131(4)°, γ = 102.452(3)°, V = 638.6(3) ų, and Z = 2; R ₁ for 1897 observed reflections [I > 2σ(I)] was 0.0171. In 2, Cu(II) was also a slightly distorted square pyramid formed by two oxygens and one nitrogen from ctssb, one oxygen from another ctssb, and one water molecule. The complex formed a 1-D chain through O–S–O bridge of ctssb ligand. The 1-D chain further constructed a double chain through O?H ··· O hydrogen bonds.     

Metal Derivatives of 1,3‐Imidazolidine‐2‐thione with Divalent d10 Metal Ions (Zn–Hg) : Synthesis and Structures

Reactions of divalent Zn‐Hg metal ions with 1,3‐imidazolidine‐2‐thione (imdtH₂) in 1 : 2 molar ratio have formed monomeric complexes, [Zn(η¹‐S‐imdtH₂)₂(OAc)₂] ( 1 ), [Cd((η¹‐SimdtH₂)₂I₂] ( 2 ), [Cd(η¹‐S‐imdtH₂)₂Br₂] ( 3 ), and [Hg(η¹‐S‐imdtH₂)₂I₂] ( 4 ). Complexes 1 – 4 , have been characterized by elemental analysis (C, H, N), spectroscopy (IR, ¹H, NMR) and x‐ray crystallography ( 1 ‐ 4 ). Hydrogen bonding between oxygen of acetate and imino hydrogen of ligand, {N(2)–H(2C)···O(2)^#} in 1 , ring CH and imino hydrogen, {C(2A)–H(2A)···Br(2)^#} in 3 have formed H‐bonded dimers. Similarly, the interactions between molecular units of complexes 2 and 4 have yielded 2D polymers. The polymerization occurs via intermolecular interactions between thione sulfur and imino hydrogen, {N(2)–H(2)···S(1)^#}, imino hydrogen and the iodine atom, {NH(1)···I(2)^#} in 2 and imino hydrogen – iodine atom {N(2A)–H(2A)···I(2)} and I···I interaction in 4 . Crystal data: [Zn(η¹‐S‐imdtH₂)₂(OAc)₂] ( 1 ), C₁₀H₁₈N₄O₄S₂Zn, orthorhombic, Pbcn, a = 9.3854(7) Å, b = 12.4647(10) Å, c = 13.2263(11) Å; V = 1547.3(2) ų, Z = 4, R = 0.0280 [Cd((η¹‐S‐imdtH₂)₂I₂] ( 2 ), C₆H₁₂CdI₂N₄S₂, orthorhombic, Pnma, a = 13.8487(10) Å, b = 14.4232(11) Å, c = 7.0659(5) Å; Z = 4, V = 1411.36(18) ų, R = 0.0186.     

The structure of di-μ-chloro- bis - {chloro( N,N -diethylethane-1,2-diamine-κ 2)copper(II)}

Dichloro(N,N-diethyl-ethane-1,2-diamine)copper(II) has copper(II) ions in square pyramidal coordination. The two nitrogen atoms of the diamine {Cu–N_primary?=?1.979(3), Cu–N_tertiary?=?2.108(2)?Å} and two chloride ions are in the basal plane {Cu–Cl1?=?2.2680(9), Cu–Cl2?=?2.2989(8)?Å}. A centrosymmetrical dimer di-μ-chloro-bis{chloro(N,N-diethylethane-1,2-diamine-κ²)copper(II)}, C₆H1₆Cl₂CuN₂, is formed by axial coordination by Cl2, trans to the tertiary nitrogen, to a second copper(II) ion, with Cu?···?Cuⁱ?=?3.4855(9) and Cl2–Cuⁱ?=?2.7860(8)?Å. The dimer is also linked by H-bond N1–H?···?Cl1ⁱ.     

Synthesis,structure and antiproliferative activity of dinuclear ruthenium arene complexes with differently coordinated thiosemicarbazones

A series of di‐nuclear ruthenium arene complexes with TSC ligands ([(η⁶‐p‐cymene)Ru(N¹,S‐TSC)]₂Cl₂, A‐type, 1 and 2 ) and their corresponding analogues ([(η⁶‐p‐cymene)Ru(N²,S‐TSC)]₂Cl₂, B‐type, 3 and 4 ), in which TSCs act as different coordination mode, have been synthesized and structurally characterized by a variety of physical methods. The molecular structures of 1 , 3 and 4 were determined using single‐crystal X‐ray diffraction analysis. The Gibbs free energy of the two examples of the two types of complexes ( 1 and 3 ) and bonding order in their single‐crystals were discussed using density functional theory (DFT) calculations. The compounds were further evaluated for their in vitro antiproliferative activities against several cancerous and HEK‐293 T noncancerous cell lines, and the results indicate that B‐type complexes show stronger cytotoxicity than A‐type complexes. Furthermore, the interactions of the compounds with DNA were investigated by electrophoretic mobility spectrometry studies.     

Syntheses and crystal structures of cis - and trans -copper(II) complexes of L-arginine

Two copper(II) complexes of L-arginine, trans-[Cu(l-Arg)₂(NO₃)]NO₃ · 3H₂O (1) and {cis-[Cu(l-Arg)₂](NO₃)₂ · 3H₂O} _n (2) (Arg = arginine) were prepared by reaction of Cu(NO₃)₂ · 3H₂O and L-arginine in acetone and aqueous solution, respectively. X-ray analysis reveals 1 crystallizes in a monoclinic system, P2₁ with a = 10.3857(15), b = 16.885(3), c = 15.9586(19) Å, β = 15.9586(19)°, Z = 4, V = 2654.2(6) ų. The copper(II) centers lie in a distorted N₂O₃ square-pyramidal environment. While 1 adopts a mononuclear structure, and the axial position occupied by a nitrate with Cu1–O9 = 2.535 Å and Cu2–O20 = 2.581 Å, 2 features a 1-D infinite chain structure. In 1, adjacent monomeric units connect with each other to give a 2-D layer structure of (4, 4) nets through hydrogen bonds between the guanidinium and carboxylic groups of arginine, and 2-D layers further assemble to a 3-D supermolecular structure via a series of inter-layer hydrogen bonds.     

Spectroscopic,electrochemical and X-ray crystallographic properties of a novel palladium(II) complex of thioamide deprotonated di-2-pyridyl ketone thiosemicarbazone (dpktsc-H)−

The reaction between di-2-pyridyl ketone thiosemicarbazone (dpktsc) and PdCl₂(CH₃CN)₂, generated in situ from the reaction between PdCl₂ and CH₃CN, gave the unprecedented [Pd₂Cl₃(κ⁵-N_py,N_im,S,N_py,N_am-dpktsc-H)]·2CH₃CN (1) complex (py = pyridine, im = imine and am = amide). The identity of 1 was confirmed via its elemental analysis and spectroscopic properties. Infrared and ¹H-NMR spectra confirmed the coordination of (dpktsc-H)^? to the palladium ions. The electronic absorption spectra measured in dmso and dmf and density functional theory (DFT) calculations revealed metal-to-ligand charge-transfer (MLCT), d–d and intra-ligand charge-transfer (ILCT) electronic transitions. X-ray structural analysis on a crystal of [Pd₂Cl₃(κ⁵-N_py,N_im,S,N_py,N_am-dpktsc-H)]·H₂O (2) grown from dmf solution of 1 confirmed its formulation and showed the solid-state structure contains a web of molecules locked via a network of non-covalent interactions. Electrochemical measurements on 1 in dmf revealed metal- and ligand-based redox processes. In contrast to the electrochemical decomposition of uncoordinated dpktsc, coordinated (dpktsc-H)^? in 1 does not undergo electrochemical decomposition. Electrochemical titrations of 1 with p-toluenesulfonic acid monohydrate (p-TSOH) revealed electro-catalytic proton reduction. Over-potential (η) of 180 mV for the H₂ evolution was observed and is comparable to several molecular electro-catalysts for proton reduction. Controlled-potential electrolysis confirmed the electro-catalytic proton reduction by the Pd-complex. Electrochemical reactions of CO₂ in the presence of 1 exhibited a proton dependence, and metal- and ligand-based electrochemical reaction.     

Synthesis,structural characterization,oxygen sensitivity,and antimicrobial activity of ruthenium(II) carbonyl complexes with thiosemicarbazones

[Ru(CO)(PPh₃)₂(η³-O,N³,S-TSC¹)] (1), [Ru(Cl)(CO)(PPh₃)₂(η²-N³,S-TSC²)] (2), and [Ru(Cl)(CO)(PPh₃)₂(η²-N³,S-TSC³)] (3) have been prepared by reacting [Ru(H)(Cl)(CO)(PPh₃)₃] with the respective thiosemicarbazones TSC¹ (2-hydroxy-3-methoxybenzaldehyde thiosemicarbazone), TSC² (3-hydroxybenzaldehyde thiosemicarbazone), and TSC³ (3,4-dihydroxybenzaldehyde thiosemicarbazone) in a 1?:?1 M ratio in toluene and all of the complexes have been characterized by UV–vis, FT-IR, and ¹H and ³¹P NMR spectroscopy. The spectroscopic studies showed that TSC¹ is coordinated to the central metal as a tridendate ligand coordinating via the azomethine nitrogen (C=N), phenolic oxygen, and sulfur to ruthenium in 1, whereas TSC² and TSC³ are coordinated to ruthenium as a bidentate ligand through azomethine nitrogen (C=N) and sulfur in 2 and 3. Oxygen sensitivities of 1–3 and [Ru(Cl)(CO)(PPh₃)₂(η²-N³,S-TSC⁴)] (4), and antimicrobial activities of 1–3 have been determined.     

Two copper complexes based on nitronyl nitroxide with different halides: structures and magnetic properties

Complexes based on different halogen-substituted nitronyl nitroxide radicals and Cu(II), Cu₃(hfac)₆(NIT-Ph-F)₂ (1) and Cu₃(hfac)₆(NIT-Ph-Cl)₂ (2) (hfac = hexafluoroacetylacetonate; NIT-Ph-F = 2-(4′-fluorophenyl)-4,4,5,5-tetramethyl-imidazoline-1-oxyl-3-oxide; NIT-Ph-Cl = 2-(4′-chlorphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide), were synthesized and characterized structurally and magnetically. X-ray crystal structure analyses show that 1 and 2 have similar centrosymmetric five-spin structures consisting of three Cu(II) ions bridged by two nitroxide ligands. The Cu(II) is coordinated by six oxygens to form an octahedron, while the five coordination of the terminal Cu(II) ion is square pyramidal. Magnetic measurements reveal strong antiferromagnetic interactions between Cu(II) ions and radicals in 1 (J = ?38.9 cm^?1) and weak antiferromagnetic interactions between Cu(II) ions and radicals in 2 (J = ?1.23 cm^?1), which may be explained by the bond length of the Cu–O_rad (2.468(2) Å) in 1, which is shorter than that (2.514(2) Å) in 2, and the dihedral angle (73.17(1)°) of the plane O7–O8–Cu(2)–O7A–O8A with the moiety O5–N1–C11–N2–O6 in 1 is smaller than (77.82(1)°) in 2.     

COPPER CATALYZED HYDROLYSIS OF TRIAZINE: SYNTHESIS AND STRUCTURE OF Cu(HN = CHNHCH = NH)2(ClO4)2

Abstract

Reaction of Cu(ClO₄)₂·6H₂O with 1,3,5-triazine in 95% ethanol resulted in partial hydrolysis of the triazine ring and isolation of bis(1,3,5-triaza-1,4-pentadieno) copper(II) perchlorate, (1). Compound 1 crystallizes as violet needles. Crystal data for Cu(HN = CHNHCH = NH)₂(ClO₄)₂ are: monoclinic, space group: C2/c, a = 13.342(3), b = 11.186(2), c = 18.045(4) Å, β = 99.09(3)°, V = 2659.3(10) ų, Z = 8, D_calc = 2.021 Mg/m³, μ = 2.096 mm^?1, F(000) = 1624, MoK_α (γ = 0.71069Å), R = 0.063 for 1597 unique observed [≥Fα3σ(F)] reflections and 196 parameters. The bis-chelated copper(II) ion contains a planar coordination geometry with Cu-N_(ave) = 1.97Å and the perchlorate ions weakly coordinated (Cu - 0 = 2.84Å) in the axial positions.     

A tetranuclear copper(II) complex: crystal structure,assembly, EPR,electrochemistry and magnetism

A tetranuclear copper(II) complex, [Cu₂L]₂(ClO₄)₂ · 4H₂O (1), where H₃L = N,N′-bis(4-(3′-formyl-5′-chlorosalicyclidene)iminoethyl)-4-chloro-2,6-bimethyliminophenol, has been synthesized and structurally characterized by ES-MS, IR and X-ray crystallography. The complex is a dimer of two dinuclear copper(II) acylic enantiomorph subunits ([Cu₂L]ClO₄ · 2H₂O), held together by π–π, coordination and hydrogen bond interactions. The Cu–Cu separation in each subunit, bridged by one phenoxide, is 3.228 Å, and the shortest distance of Cu–Cu between the two subunits is 3.252 Å. There are two crystallographically unique copper(II) environments, one (Cu1) is square-based pyramidal with O₃N₂ donor set, another (Cu2) square planar with O₂N₂ donor set. The cyclic voltammogram of the complex shows that it undergoes two stepwise reduction processes, E _pc = ?0.707 and ?0.850 V, respectively. Magnetic measurements in the 2–300 K range indicate strong antiferromagnetic interactions between Cu(II) ions in each subunit with the exchange constant J = ?211(2) cm^?1. The observation has been rationalized on the basis of the effective magnetic pathway.     

Synthesis,structures, and magnetic properties of two pyrazolato-bridged trinuclear copper(II) complexes

One nonlinear and one linear trinuclear copper(II) complex [Cu₃(dien)₂(pdc)₂CH₃OH]₂?·?6CH₃OH (1) and [Cu₃(pdc)₂(CH₃OH)₆(H₂O)₄] (2) were prepared and characterized structurally, where dien is diethylenetriamine and pdc^3? the trianion of 3,5-pyrazoledicarboxylic acid. Both complexes consist of 3,5-pyrazoledicarboxylato-bridged trinuclear copper(II) centers. In 1, copper(II) ions are five-coordinate in distorted square pyramids with bond angles 164.78° for Cu(1)–Cu(2)–Cu(3) and 164.51° for Cu(4)–Cu(5)–Cu(6). In 2, the three copper(II) ions are six-coordinate with elongated octahedral geometry. The trinuclear units of 1 and 2 interact through hydrogen bonds to form 3-D and 2-D supramolecular networks, respectively. Variable temperature magnetic susceptibility measurements show that 1 and 2 are antiferromagnetically coupled with J values of ?11.2 and ?13.3?cm^?1.     

Differing Coordination Modes of (O‐Alkyl)‐p‐Ethoxyphenyldithiophosphonato Ligands in Copper(I), Silver(I) and Gold(I) Triphenylphosphine Complexes

The three (O‐methyl)‐p‐ethoxyphenyldithiophosphonato triphenylphosphine complexes of copper, silver and gold, [(Ph₃P)_nM{S₂P(OMe)C₆H₄OEt‐p}] (M = Cu, n = 2; M = Ag, Au, n = 1) investigated structurally by X‐ray diffraction exhibit remarkable structural differences. The copper compound is a four‐coordinate chelate monomer with Cu–S 2.4417(6) and 2.5048(6) Å; P–Cu–S 104.24(2)–114.01(2)°; Cu–S–P 82.49(3)° and 80.85(2)°. The silver compound is a cyclic dimer with bridging dithiophosphonato ligands and three‐coordinate silver atoms [Ag–S 2.5371(5) and 2.6867(5) Å; P–Ag–S 122.88(2)° and 122.17(2)°; Ag–S–P 89.32(2)° and 103.56(2)°]. The gold compound is monomeric with linear dicoordinate gold [Au–S 2.3218(6) Å; P–Au–S 177.72(2)°, Au–S–P 100.97(3)°].     

Two Novel CuII Phenanthroline Adipato Complexes with π‐π Stacking Interactions: [Cu(phen)2(C6H8O4)] · 4.5 H2O and [(Cu2(phen)2Cl2)(C6H8O4)] · 4 H2O

The blue copper complex compounds [Cu(phen)₂(C₆H₈O₄)] · 4.5 H₂O ( 1 ) and [(Cu₂(phen)₂Cl₂)(C₆H₈O₄)] · 4 H₂O ( 2 ) were synthesized from CuCl₂, 1,10‐phenanthroline (phen) and adipic acid in CH₃OH/H₂O solutions. [Cu(phen)₂‐ (C₆H₈O₄)] complexes and hydrogen bonded H₂O molecules form the crystal structure of ( 1 ) (P1 (no. 2), a = 10.086(2) Å, b = 11.470(2) Å, c = 16.523(3) Å, α = 99.80(1)°, β = 115.13(1)°, γ = 115.13(1)°, V = 1617.5(5) ų, Z = 2). The Cu atoms are square‐pyramidally coordinated by four N atoms of the phen ligands and one O atom of the adipate anion (d(Cu–O) = 1.989 Å, d(Cu–N) = 2.032–2.040 Å, axial d(Cu–N) = 2.235 Å). π‐π stacking interactions between phen ligands are responsible for the formation of supramolecular assemblies of [Cu(phen)₂(C₆H₈O₄)] complex molecules into 1 D chains along [111]. The crystal structure of ( 2 ) shows polymeric [(Cu₂(phen)₂Cl₂)(C₆H₈O₄)_2/2] chains (P1 (no. 2), a = 7.013(1) Å, b = 10.376(1) Å, c = 11.372(3) Å, α = 73.64(1)°, β = 78.15(2)°, γ = 81.44(1)°, V = 773.5(2) ų, Z = 1). The Cu atoms are fivefold coordinated by two Cl atoms, two N atoms of phen ligands and one O atom of the adipate anion, forming [CuCl₂N₂O] square pyramids with an axial Cl atom (d(Cu–O) = 1.958 Å, d(Cu–N) = 2.017–2.033 Å, d(Cu–Cl) = 2.281 Å; axial d(Cu–Cl) = 2.724 Å). Two square pyramids are condensed via the common Cl–Cl edge to centrosymmetric [Cu₂Cl₂N₄O₂] dimers, which are connected via the adipate anions to form the [(Cu₂(phen)₂Cl₂)(C₆H₈O₄)_2/2] chains. The supramolecular 3 D network results from π‐π stacking interactions between the chains. H₂O molecules are located in tunnels.