Syntheses,crystal structures and properties of Cd(II) and Ag(I) complexes based on 2-p-methylphenyl-5-(2-pyridyl)-1,3,4-thiadiazole

Abstract

Complexes of [CdL₂(NO₃)₂]·1.5H₂O and [Ag₂(μ-L)₂(NO₃)₂] were synthesized by the reactions of 2-p-methylphenyl-5-(2-pyridyl)-1,3,4-thiadiazole (L) with Cd(NO₃)₂·4H₂O and AgNO₃, respectively. Their structures were determined by single crystal X-ray diffraction. The photophysical property and thermal stability were characterized by FT???IR, UV???Vis absorption, fluorescence, and thermogravimetric analysis (TGA). Both complexes belong to the triclinic system with space group p???1. The central metal of [CdL₂(NO₃)₂]·1.5H₂O has a distorted octahedral geometry [CdN₄O₂], while two central Ag(I) atoms of [Ag₂(μ-L)₂(NO₃)₂] exhibit distorted tetrahedral geometries [AgN₃O].     

Syntheses and crystal structures of two new cobalt(II) complexes derived from 3,5-bis(pyridin-2-yl)-4-amino-1,2,4-triazole

Two different cobalt(II) complexes have been synthesized from room-temperature solution reaction or solvothermal reaction of CoCl₂, KSCN, 3,5-bis(pyridin-2-yl)-4-amino-1,2,4-triazole and MeOH. X-ray crystallography shows that the product obtained at ambient temperature is a mononuclear species, while the product obtained by solvothermal method is a dinuclear complex incorporating an in situ deaminated ligand.     

Synthesis and crystal structures of complexes of Ni (II) to chiral Schiff bases of (R)- and (S)-serine with (S)- and (R)-2-N-(N′-benzylprolyl)-aminobenzophenone

The three-dimensional molecular and crystal structures of a pair of enantiopure mirror complexes of Ni (II) to chiral Schiff bases of (R)- and (S)-serine with (S)- and (R)-2-N-(N′-benzylprolyl)-aminobenzophenone (BPB), denoted as (S,R)-BPB-Ser-Ni and (R,S)-BPB-Ser-Ni, respectively, have been determined by X-ray diffraction. The complexes crystallize in the orthorhombic space group P2 ₁ 2 ₁ 2 ₁ with unit cell parameters: a = 10.050(2) Å, b = 10.100(2) Å, c = 26.514(5) Å, V = 2691.3(9) ų, and Z = 4 for (S,R)-BPB-Ser-Ni; and a = 9.878(2) Å, b = 10.130(2) Å, c = 26.304(5) Å, V = 2632.1(9) ų, and Z = 4 for (R,S)-BPB-Ser-Ni. The Ni atom is square-planar-coordinated to N(1), N(2), O(4), and N(3) of the Schiff base with minor distortion. The hydroxymethyl group on the serine moiety is axial to the coordination plane and parallel to the neighboring phenyl group.     

Metal complexes of chiral pyridine ligands. X-ray structure of nitratobis {2-(2S)-2-pyrrolidinyl]pyridine} copper (II) nitrate

Cobalt(II), nickel(II), and copper(II) complexes of 2-[(2S)-2-pyrrolidinyllpyridine (L) have been synthesized and characterized. The crystal structure of the complex [Cu(L)₂(NO₃)]NO₃ has been determined by X-ray diffraction. Crystals are monoclinic, space groupP2+, witha=10.766(3).b=7.525(2),c=13.447(4) Å. =104.64(2)°. and Z=2. The structure consists of [Cu(L)₂(NO₃)]⁺ cations and NO ₃ ^t- anions. The copper atom has a distorted trigonal bipyramidal coordination geometry with the two pyrrolidine nitrogens and one nitrate oxygen occupying the equatorial positions and the two pyridine nitrogens at the apices. The crystalline cohesion is ensured by a network of hydrogen bonds involving the pyrrolidine groups as donors and both coordinate and uncoordinate nitrates as acceptors.     

Synthesis, crystal structures, and properties of two manganese(II)-nitroprusside complexes

Two new manganese(II)-1,10-phenanthroline-nitroprusside complexes, [Mn(phen)₃][Fe (CN)₅(NO)]⋯2H₂O⋯0.25CH₃OH (1) and [Mn(phen)₂(H₂O)₂][Fe(CN)₅(NO)]⋯H₂O (2) (where phen is 1,10-phenanthroline) have been synthesized and characterized by X-ray diffraction, electronic paramagnetic resonance (E.P.R.) and IR analyses. Complex 1 crystallizes in the monoclinic space group P2₁/n, with lattice parameters a = 10.0441(15) Å, b = 19.668(2) Å, c = 19.938(3) Å,  β =100.427(14)°, V = 3873.7(10) ų, Z = 4; complex (2) crystallizes in the monoclinic space group C2/c, with a = 17.120(2) Å, b = 13.7925(19) Å, c = 14.4362(17) Å, β = 107.962(12)°, V = 3242.6(7) ų, Z = 4. In the two compounds, three phen ligands 1, or two phen ligands and two cis-related aqua molecules 2, are in a distorted octahedral arrangement around the Mn(II) ion. The nitroprusside anion, [Fe(CN)₅(NO)]²⁻, acts as a counterion. It is intriguing that in complex 2 no cyano bridges are present with two water molecules coordinated to the Mn(II) ion considering that usually the cyano nitrogen atoms are strong donors and could readily replace the coordinating solvent water molecules. Abundant hydrogen bond interactions and π–π stacking between the phen rings in two complexes lead to three-dimensional supramolecular networks.     

The crystal and molecular structures of two bromo bis(N,N-dipropylthiocarbamoyl) sulfidocopper(I) complexes

The reaction of copper(I) bromide, CuBr, with the tetraalkylthiurammonosulfides R₄tms (R = ⁱPr, ⁿPr) affords the copper(I) complexes ⁱPr₄tmsCuBr (I) (C₁₄H₂₈BrCuN₂S₂, orthorhombic, Pna2₁, Z = 4, a = 12.487(2), b = 12.699(2), c = 12.742(2) Å) and ⁿPr₄tmsCuBr (II) (C₁₄H₂₈BrCuN₂S₃, monoclinic, P2₁/n, Z = 4, a = 9.092(5), b = 23.408(11), c = 10.082(7) Å, = 104.90(5)°), which exist in the solid as monomeric units featuring three-coordinate copper(I). The ligands are bidentate and coordination is completed by the bromine atoms. The configurations of the six-membered metal-ligand ring in (I) and (II) are more severely distorted than the previously reported structurally related complexes of ethyl series. The crystal structural studies are complemented and confirmed by IR and ¹H-NMR spectroscopies, as well as room temperature, magnetic, solution conductivity, and molecular weight studies.     

Polymeric copper(II)-orotato complexes, [(C5H2N2O4)Cu(H2O)2]n

The compound [(C₅H₂N₂O₄)Cu(H₂O)₂]_n has been synthesized and its structure determined at room temperature. The primary coordination sphere at the Cu ion is square planar with the orotate dianion coordinating at the metal through heterocyclic nitrogen atom and adjacent oxygen of the carboxylate group, the remaining coordination sites are occupied by two water molecules. The orotate dianion is tricoordinated to one copper via N₁ and one oxygen of the carboxylato group and to another copper atom via the other oxygen of the carboxylato group. The coordination at copper is extended to five by the other oxygen of the carboxylate group of another orotate molecule. Thus, the molecules are associated to form chains, the carboxylato group acting as a bridge between the metal ions, the orotato-group being tridentate. The title compound crystallizes in the monoclinic space group. P2₁/n₁ with a = 9.515(5), b = 6.925(2), c = 11.861(6) Å, = 95.285(9)°, D _calc = 2.17 g cm^–3, and z = 4.     

X-ray crystal structures of twocis-Mo(CO)4{(Ph2PO)2P(O)R} (R=Me,MeO-p-C6H4) complexes with unusual Mo-PPh2-O-P(O)R-O-PPh2 chelate rings

The X-ray crystal structures of twocis-Mo(CO)₄{(Ph₂PO)₂P(O)R} (I:R=Me; II: R=C₆H₄-p-OMe) complexes are presented. Complex I crystallizes in the monoclinic space groupP2₁/n (a=11.566(1),b=10.045(2),c=25.959(4)Å;=97.64(1)°;V=2989.0 ų;Z=4). Complex II crystallizes in the triclinic space group P¯1 (a=8.868(2),b=11.552(2),c=16.818(3)Å,=78.32(1)°,=93.70(2)°, =86.59(2)°,V=1679.0 ų,Z=2). The coordination geometry of the molybdenum in each of these complexes is a slightly distorted octahedron. The six-membered chelate rings in these complexes have twist boat configurations with both ends flattened. The two rings differ in the degree of twisting in the boat and in the degree to which both ends of the boat are distorted from the ideal configurations. The twisting is greater in II, but the distortion is greater in I. Both appear to be due to the differing sizes of the substituent on the phosphonate phosphorus with larger substituents giving less twisting and flattening.     

Synthesis and crystal structure of the copper(II) complex with novel Schiff base ligand: Cu(C8H7O2N)2(OH2)

The title complex Cu(C₈H₇O₂N)₂(OH₂) crystallized in the orthorhombic space group, Pbca with unit cell parameters: a = 15.242(2), b = 11.782(4), c = 17.946(4) Å, and Z = 8. Two nitrogen atoms, two phenolic oxygen atoms of the ligand, and one water molecule are coordinated with copper to form a distorted tetragonal pyramidal polyhedron.     

(C2N2H10)2Mg(HP2O7)2·2H2O synthesis and crystal structure

(C₂N₂H₁₀)₂Mg(HP₂O₇)₂·2H₂O, is a new inorganic organic hybrid structure. It has been synthetized using wet chemistry. Its crystal structure consists of cis- and trans-edge sharing [MgO₄(H₂O)₂] octahedra resulting in chains, which are linked via [HP₂O₇] units to form [Mg(HP₂O₇)₂(H₂O)₂]⁴⁻ layers. The Mg²⁺ cations and the ethylendiammonium cations are located on centers of inversion. The ethylendiammonium cations are alternately located in the interlayer space. The cohesion of the crystal is well ensured by coulombic interactions between anions and cations and by several hydrogen bonds. The diphosphate anion shows an eclipsed conformation.     

X-ray crystal structure oftrans-dichlorobis(2,4,6-collidine)-copper(II)

The X-ray crystal structure oftrans-dichlorobis(2,4,6-collidine)copper(II) has been determined. Dark blue crystals of the complex crystallize in the monoclinic space group P2₁/c, with cell dimensionsa=7.527(3),b=14.732(4),c=7.951(4)Å and=92.79(9)°;V=880.6(6)ų andZ=2. 949 unique reflections withI _net>3(I) on refinement afforded values ofR=0.041 andR _w =0.048.     

Synthesis, characterization, and X-ray crystal structure of di-(2,4-imidazolidinedione-5-ethyl)disulfide, C10H14N4O4S2

Di-(2,4-imidazolidinedione-5-ethyl)disulfide or homocystine hydantoin, C₁₀H₁₄N₄O₄S₂ (I), crystallizes in the non-centrosymmetric space group P2₁ (No. 4) with two molecules in the unit cell with a = 7.132(1), b = 9.282(2), c = 10.770(2) Å and = 105.68(1)°. The two imidazolidinedione rings are planar with a dihedral angle of 46.9°. The rings are joined by a diethyl disulfide bridge at chiral centers on the rings. The C-S-S-C torsion angle is –80°(–sc). The absolute stereochemistry of the chiral centers was determined to be (5S, 5S), = + 0.92 (11). Important bond distances include: S-S = 2.022(4); S-C (mean) = 1.809(8); and C=O (mean) = 1.224(7) Å. The compound is stabilized by a network of intermolecular carbonyl-to-amine hydrogen bonding and van der Waals cohesive forces.     

Crystal structures of three methylmercury(II) complexes with thiazolidine-2-thione

The crystal structures of three CH₃Hg⁺ complexes with 1,3-thiazolidine-2-thione (HT) are reported. The cationic [(CH₃Hg)HT]NO₃ complex is monoclinic, space group P2₁/c,a=7.158(14),b=10.156(7),c=13.472(12) Å,=108.21(4)°,Z=4. The structure was refined toR=0.045. The [(CH₃Hg)HT]⁺ cation contains a CH₃Hg⁺ group bonded to the exocyclic S atom of the ligand retaining its N-H proton. This proton is lost and the CH₃Hg⁺ group remains bonded to sulfur in the neutral [(CH₃Hg)T] compound (hexagonal, P6₃,a=13.502(8),c=6.984(7) Å,Z=6,R=0.027). The [(CH₃Hg)₂T]NO₃ compound (monoclinic, C2/c,a=25.200(10),b=7.029(6),c=17.946(8),=128.99(3)°,Z=8,R=0.047) contains complex cations in which the CH3Hg⁺ groups are bonded to N and the exocyclic S atom. This series of compounds shows that the exocyclic S atom is always the first target for the CH₃Hg⁺ group, which is also found to bind to nitrogen in the 2:1 compound. No coordination is observed with the endocyclic S site, which does not even participate in intermolecular H-bonding or HgS contacts in the solids.     

Specific features of the structures of d 2-Rhenium(V) monomeric octahedral oxo complexes: I. Structure of d 2-Re(V) mono-oxo compounds with halogen ligands trans-positioned to O(oxo) ligands

The specific features of the structure of rhenium(V) mononuclear octahedral mono-oxo complexes with halogen ligands (F, Cl, Br), trans-positioned to multiply bonded oxo ligands, are considered.     

X-ray crystal structure oftrans-dichlorobis(2,6-lutidine)palladium(II)

The X-ray structure oftrans-(2,6-lutidine)₂PdCl₂ has been determined. Golden orange crystals of the complex crystallize in the triclinic space group , with cell dimensionsa=7.6950(8),b=7.9705(10),c=8.0485(8)Å, =116.967(9), =113.343(8), and =93.836(9)°;V=385.18(7)ų andZ=2. 1336 unique reflections withI _net>3 (I) on refinement afforded values ofR=0.018 andR _w=0.023.     

Synthesis and crystal structure of thiosemicarbazide complexes of nickel(II) and copper(II)

Thiosemicarbazide complexes of nickel(II) [Ni(TSC)₂](HSal)₂ (I) and copper(II) [Cu(TSC)₂](HSal)₂ (Ia) (TSC is thiosemicarbazide and HSal is a salycilate anion), as well as complexes [Ni(TSC)₂](SO₄) · 2H₂O (II) and [Ni(TSC)₃]Cl₂ · H₂O (III), are synthesized and characterized by IR spectroscopy and X-ray diffraction. Monoclinic crystals I and Ia are isostructural; space group P2₁/n, Z = 2. Crystals II are monoclinic, space group P2₁/m, Z = 2. Crystals III are orthorhombic, space group Pbca, Z = 8. In I and Ia, two planar salycilate anions sandwich a planar centrosymmetric [Ni(TSC)₂]²⁺ cation to form a supermolecule. The cation and anions are additionally bound by hydrogen bonds. Other hydrogen bonds connect supermolecules into planar layers. In structure II, centrosymmetric [Ni(TSC)₂]²⁺ cations are connected by ??-stacking interactions into supramolecular ensembles of a specific type. The ensembles, water molecules, and (SO₄)^2? anions are bound in the crystal via hydrogen bonds. In the [Ni(TSC)₃]²⁺ cation of structure III, ligands coordinate the Ni atom by the bidentate chelate pattern with the formation of five-membered metallocycles. These metallocycles have an envelope conformation unlike those in I and II, which are planar. In III (unlike in analogous complexes), a meridional isomer of the coordination octahedron of the Ni atom is formed. Together with Cl1^? and Cl2^? anions, cations form supermolecules, which are packed into planar layers with a square-cellular structure. The layers are linked by hydrogen bonds formed by crystallization water molecules that are located between the layers.     

Synthesis and properties of palladium(II) complexes with sulfur ligands

Complexes of L-2 thiolhistidine (th) and 2-mercaptoimidazole (miz) with Pd(II) were synthesized, Pd(th)₄(NO₃)₂ and Pd(miz)₄Cl₂, and their structure determined by FTIR, UV/VIS, NMR, mass spectroscopy, and X-ray crystallography. For comparison, a Pd(II) complex with thiourea (tu), Pd(tu)₄Cl₂, was prepared. This compound has been reported in the literature. Spectral evidence indicates a single coordination site between the Pd(II) and S for all complexes. A Pd-S stretch band was identified for all complexes. NMR spectra provided evidence for deshielding effects in the complexes from that of its ligands. Charge transfer bands were identified in the UV/VIS spectra for the new complexes as well. The crystal structure for Pd(miz)₄Cl₂ was determined. Unit cell data was found to be:a=8.102(3)Å,b=8.300(3)Å,c=8.304(3)Å. The crystal system is triclinic and the space group isP ¯1.     

X-ray crystal structure of tetraaquabis (xanthosinato)nickel(II) hexahydrate

The complex [Ni(XsH_–1)₂(H₂O)₄]·6H₂O (XsH_–1: xanthosinate) was isolated from the reaction of nickel carbonate with xanthosine in aqueous solution. The octahedral coordination is supported by the reflectance measurements. Single-crystal X-ray diffraction studies show that the crystals belong to the triclinic P1 space group, with a = 7.152(1), b = 8.830(1),c = 13.783(1) Å, = 82.024(1)°, = 86.155(1)°, = 70.900(1)°, and D = 1.643 mg/m³, forZ = 1. Nickel is six coordinate with four water molecules, and two N7 atoms from xanthosinato ligands. A complicated hydrogen-bonding network is present, all possible donors taking part in it.     

Synthesis and crystal structures of two new complexes [M(OH2)(HDPA)2]·3H2O (M = Mn, Co)

Two new transition metal complexes of [M(OH₂)(HDPA)₂]·3H₂O (M=Mn(1); M=Co(2)) (H₂DPA, 2,6-pyridine-dicarboxylic acid) have been prepared at room temperature from the reaction of MCl₂·6H₂O (M=Mn or Co) and H₂DPA in the mixed solvent of H₂O and EtOH in the presence of piperazine, and were characterized by X-ray analysis, elemental analysis. X-ray analysis reveals that the coordination geometries of Mn²⁺ and Co²⁺ are of octahedron and severely distorted square-based pyramid, respectively. Crystal data: [Mn(OH₂)(HDPA)₂]·3H₂O (1), Mr=459.23, monoclinic, P2(1)/n, a=7.0056(3), b=(23.8125(12), c=10.7444(3) ?, β=99.834(2)°, Z=4, V=1766.28(13) ?³, R ₁=0.0586, wR ₂=0.1448 [I>2σ(I)]; Co(OH₂)(HDPA)₂]·3H₂O (2), Mr=463.22, monoclinic, P2(1)/n, a=7.0014(2), b=23.8346(7), c=10.7212(4) ?, β=99.8540(10)°, Z=4, V=1762.71(10) ?³, R ₁=0.0474, wR ₂=0.1366 [I>2σ(I)].