Synthesis and crystal structures of nitratocobaltates Na2[Co(NO3)4], K2[Co(NO3)4], and Ag[Co(NO3)3] and potassium nitratonickelate K2[Ni(NO3)4]

The cobalt(II) and nickel(II) nitrate complexes with an island structure (Na₂[Co(NO₃)₄] (I) and K₂[Co(NO₃)₄] (II)] and a chain structure [Ag[Co(NO₃)₃] (III) and K₂[Ni(NO₃)₄] (IV)] are synthesized and investigated using X-ray diffraction. In the anionic complex [Co(NO₃)₄]^2? of the crystal structure of compound I, the Co coordination polyhedron is a twisted tetragonal prism formed by the O atoms of four asymmetric bidentate nitrate groups. In the anion [Co(NO₃)₄]^2? of the crystal structure of compound II, one of the four NO₃ groups is monodentate and the other NO₃ groups are bidentate (the coordination number of the cobalt atom is equal to seven, and the cobalt coordination polyhedron is a monocapped trigonal prism). The crystal structures of compounds III and IV contain infinite chains of the compositions [Co(NO₃)₂(NO₃)_2/2]^? and [Ni(NO₃)₃(NO₃)_2/2]^2?, respectively. In the crystal structure of compound III, seven oxygen atoms of one monodentate and three bidentate nitrate groups form a dodecahedron with an unoccupied vertex of the A type around the Co atom. In the crystal structure of compound IV, the octahedral polyhedron of the Ni atom is formed by five nitrate groups, one of which is terminal bidentate. The data on the structure of Co(II) coordination polyhedra in the known nitratocobaltates are generalized.     

Synthesis and crystal structure of oxonitrate complexes Cs[VO2(NO3)2], Cs[MoO2(NO3)3], and MoO2(NO3)2

Cs[VO₂(NO₃)₂] (I), MoO₂(NO₃)₂ (II), and Cs[MoO₂(NO₃)₃] (III) complexes have been obtained by crystallization from nitric solutions and studied by single-crystal X-ray diffraction. Complexes I and II contain infinite zigzag chains of similar compositions, [VO₂(NO₃)₂]⁻ and [MoO₂(NO₃)₂], in which V and Mo atoms form, respectively, trigonal- and pentagonal-bipyramidal polyhedra. Each of these polyhedrons also contains one terminal and two bridge O atoms and two terminal NO₃ groups which are monodentate and bidentate in complexes I and II, respectively. Complex III has an island structure and consists of Cs⁺ cations and [MoO₂(NO₃)₃]⁻ anions, in which the Mo atom is surrounded by one bidentate NO₃ group and two monodentate NO₃ groups and two terminal O atoms in the cis-positions; oxygen atoms form a polyhedron in the form of distorted octahedron. According to the ab initio calculation of isolated MoO₂(NO₃)₂ molecules in the gas phase and solution, the coordination environment of the Mo atom, similarly to the Cr(VI) atom in CrO₂(NO₃)₂, is formed by two bidentate nitrate groups and two terminal O atoms (polyhedron- twisted trigonal prism).     

Crystal structure of complexes of bivalent Co,Ni, and Cd with anions of benzoic and 2-(acetylamino)-5-nitrobenzoic acids

The structure of three complexes of bivalent metals (cobalt, nickel, and cadmium) with anions of benzoic (HL ¹) and 2-(acetylamino)-5-nitrobenzoic (HL ²) acids, namely, [Co₂¹ (H₂O)₂(μ-C₄H₄N₂)] _n (I), [NiL²(H₂O)₅]L² · 2H₂O (II), and [Cd(μ-L ²)₂(H₂O)₂] _n · 2nH₂O (III), is determined. In chainlike structure I, cobalt atoms are connected by bridging pyrazine molecules; structure II contains isolated complexes. In structure III, centrosymmetric (CdOCO)₂ cycles and polymeric ribbons are formed due to the coordination of the carboxylate group of the L ² ligand to two cadmium atoms.     

Crystal structure and vibrational spectra of polyamine-copper(II) complexes

The structures of [Cu(en)(H₂O)₂]SO₄ (I), [Cu(en)₂](NO₃)₂ (II) and [Cu(trien)I]I (III) have been determined by single crystal X-ray diffraction. ComplexI is monoclinic, space group C2/c, with unit cell parametera=7.232(1),b=11.725(2),c=9.768(1), =105.50(1)°, andZ=4. ComplexII is also monoclinic, space group P2₁/a, witha=7.978(2),b=9.982(4),c=8.218(3), =111.11(2)°, andZ=2. ComplexIII is orthorhombic, space group P2₁2₁2₁, witha=8.098(1),b=11.902(1),c=13.682(2), andZ=4. The structures were solved by direct methods and refined by full-matrix least-squares to finalR values of 0.031, 0.043 and 0.036 for complexesI, II, andIII, respectively. ComplexesI andII show an octahedral coordination geometry. ComplexIII shows a square pyramidal coordination geometry. ComplexI forms infinite monodimensional chains where the SO ₄ ^2– ions acts as a bridge between two neighboringen molecules. The vibrational spectra of these complexes agree well with their crystal structures. Structure and stability of seven other related Cu(II) complexes of (trien), (dien)₂, (en)₂ and (en) are inferred in this study.     

Palladium (II) compounds with diaminocarboxylic acids: Crystal structures of [Pd(H2Cdta)] · H2O, [Pd(H3Edtp)Cl] · 2H2O, and (H6Edtp)[PdCl4] · 4H2O

The crystal structures of three Pd(II) compounds with diamine tetracarboxylates in different protonation states are determined, namely, [Pd(H₂ Cdta)] · H₂O (I), [Pd(H₃ EdtpCl] · 2H₂O (II), and (H₆ Edtp)[PdCl₄] · 4H₂O (III) (R ₁ = 0.0230, 0.0313, and 0.0277 for 3040, 3377, and 3809 reflections with I > 2σ(I) for I–III, respectively). Crystals I and II are built of neutral complexes [Pd(H₂ Cdta)] and [Pd(H₃ Edtp)Cl], respectively, and crystallization water molecules. Crystal III consists of [PdCl₄]²⁻ anionic complexes, H₆ Edtp ²⁺ cations, and water molecules. In I, one of the protonated acetate groups of the H₂ Cdta ²⁻ ligand forms a very weak additional Pd-O bond [2.968(2) Å] over the 2N + 2O coordination square. In II and III, the protonated propionate groups of the H₃ Edtp ⁻ ligand and the H₆ Edtp ²⁺ cation are not involved in Pd coordination and the coordination squares consist of the 2N + O + Cl and 4Cl atoms, respectively. __________ Translated from Kristallografiya, Vol. 48, No. 2, 2003, pp. 278–282. Original Russian Text Copyright ? 2003 by Polyakova, Poznyak, Sergienko.     

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.     

Two-Dimensional Hydrogen-Bonded Polymer from Nickel(II) Tetraaza Macrocyclic Complex and Succinate Ligand

Abstract  

The reaction of [Ni(L)]Cl₂·2H₂O (L = 3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,0^1.18,0^7.12] docosane) with succinic acid (C₄H₆O₄) yields a 2D hydrogen-bonded polymer with formula [Ni(L)(C₄H₅O₄)₂] (1). This polymer complex has been characterized by X-ray crystallography, spectroscopy and cyclic voltammetry. The complex has a center of symmetry. The crystal structure of 1 exhibits a distorted octahedral geometry about Ni atom with four nitrogen atoms of the macrocycle and two oxygen atoms of the succinate ligand at the trans position. Compound 1 crystallizes in the monoclinic system C2/c with a = 14.8203(11), b = 12.3070(8), c = 17.4164(12) ?, β = 107.356(6)°, V = 3032.1(4) ?³, Z = 4. Electronic spectrum of 1 reveals a high-spin octahedral environment. Cyclic voltammetry of 1 undergoes two waves of a one-electron transfer corresponding to Ni^II/Ni^III and Ni^II/Ni^I processes.     

The crystal structure of aluminium,iron (III), and gallium acid phosphites

The structures of three acid phosphites of trivalent metals [Al(HPO₃H)₃(H₂O)] · H₂O (I), K[Fe(HPO₃H₄)] (II), and Rb₃[Ga(HPO₃H)₆] (III) have been determined. Structure I is layered, complex anions [Fe(HPO₃H)₄]⁻ form polymer chains in structure II, and structure III is insular.     

Synthesis,Properties, and Crystal Structures of Copper(II) Di-(2-picolyl)amine Complexes Containing Inorganic Salts

Abstract These complexes have been characterized by X-ray crystallography, spectroscopic, and cyclic voltammetry. In 1, the copper(II) ion has a distorted square-pyramidal geometry with three nitrogen atoms of the dpa ligand and two oxygen atoms of the nitrate anions. The crystal structure of 2 shows that the copper(II) ions are bridged by tp anion to form a dinuclear complex, in which each copper(II) ion exhibits a distorted square-pyramid with three nitrogen atoms of the dpa ligand, water molecule, and the oxygen atom of the bridging tp ligand. Cyclic voltammetric data indicate that 1 undergoes irreversible one-electron oxidation to the Cu^III and reversible one-electron reduction to the Cu^I, while 2 gives one reversible oxidation and two reversible and irreversible reduced processes. The electronic spectra and redox potentials of the complexes are influenced significantly by the anionic ligands. Graphical Abstract The reaction of [Cu(dpa)Cl₂] with K(NO₃)₂ and Na₂tp yields mononuclear and dinuclear copper(II) complexes [Cu(dpa)(NO₃)₂] (1) and [Cu₂(dpa)₂(H₂O)₂(μ-tp)](tp)·6H₂O (2) (dpa = di-(2-picolyl)amine, tp = terephthalate).      

Synthesis and Characterization of Nickel(II) Complex of 3,14-Dimethyl-2,6,13,17-Tetraazatricyclo[14,4,01.18,07.12]Docosane Containing Pyrazine-2-Carboxylate Ligand

Abstract  

The reaction of [Ni(L)]Cl₂·2H₂O (L = 3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,0^1.18,0^7.12]docosane) with pyrazine-2-carboxylic acid (H-pyc) yields mononuclear nickel(II) complex, [Ni(L)(pyc)₂]·2H₂O (1). This complex has been characterized by X-ray crystallography, electronic absorption and cyclic voltammetry. The crystal structure of 1 exhibits a distorted octahedral geometry with four nitrogen atoms of the macrocycle and two pyrazine-2-carboxylate ligands. It crystallizes in the triclinic system P-1 with a = 9.6643(17), b = 10.116(3), c = 16.99(4) ?, V = 1633(3) ?³, Z = 2. Electronic spectrum of 1 also reveals a high-spin octahedral environment. Cyclic voltammetry of 1 undergoes two waves of a one-electron transfer corresponding to Ni^II/Ni^III and Ni^II/Ni^I processes.     

Complexes in the Ni2+-imidazole-RN(CH2COO−)2 systems. The crystal structures of tris(imidazole)iminodiacetatonickel(II) monohydrate, hexa(imidazole)nickel(II) bis(N-methyliminodiacetato)nickelate(II) hexahydrate, and tetra(aqua)bis(imidazole)nickel(II) bis(N-benzyliminodiacetato)nickelate(II)

Crystals of different compositions, namely, [Ni(Ida)(Im)₃] ? H₂O (I), [Ni(Im)₆][Ni(Mida)₂] ? 6H₂O (II), and [Ni(Im)₂(H₂O)₄][Ni(Bida)₂] (III), have been precipitated from aqueous solutions of the Ni²⁺-Lig ^2?-Im systems, where Lig ^2? is Ida, Mida, and Bida, respectively. The crystal structures of I–III are determined by X-ray diffraction analysis (R = 0.0307, 0.0348, and 0.0302 for 3061, 4706, and 2882 reflections, respectively). Crystals I are built of monomeric mixed-ligand complexes and molecules of crystallization water, which are interlinked by hydrogen bonds into a three-dimensional framework. In II and III, the ligands Lig ^2? and Im form charged complexes separately. In II, the cationic and anionic layers of the complexes alternate along the c-axis. Numerous hydrogen bonds involving molecules of crystallization water link the layers into a three-dimensional framework. In III, the cationic and anionic complexes, which serve as proton donors and acceptors, respectively, are bound into layers parallel to the xy plane.     

Structural Characterization of Heterodinuclear ZnII-LnIII Complexes (Ln = Pr,Nd) with a Ring-Contracted H2valdien-Derived Schiff Base Ligand

Synthesis and structural characterization of two heterodinuclear Zn^II-Ln^III complexes with the formula [ZnLn(HL)(µ-OAc)(NO₃)₂(H₂O)_x(MeOH)_1-x]NO₃ · n H₂O · n MeOH [Ln?=?Pr (1), Nd (2)] and the crystal and molecular structure of [ZnNd(HL)(µ-OAc)(NO₃)₂(H₂O)] [ZnNd(HL)(OAc)(NO₃)₂(H₂O)](NO₃)₂ · n H₂O · n MeOH (3) are reported. The asymmetrical compartmental ligand (E)-2-(1-(2-((2-hydroxy-3-methoxybenzylidene)amino)-ethyl)imidazolidin-2-yl)-6-methoxyphenol (H₂L) is formed from N¹,N³-bis(3-methoxysalicylidene)diethylenetriamine (H₂valdien) through intramolecular aminal formation, resulting in a peripheral imidazoline ring. The structures of 1–3 were revealed by X-ray crystallography. The smaller Zn^II ion occupies the inner N₂O₂ compartment of the ligand, whereas the larger and more oxophilic Ln^III ions are found in the outer O₂O₂’ site.

Graphic Abstract

Synthesis and structural characterization of two heterodinuclear Zn^II-Ln^III complexes (Ln?=?Pr, Nd) bearing an asymmetrical compartmental ligand formed in situ from N¹,N³-bis(3-methoxysalicylidene)diethylenetriamine (H₂valdien) through intramolecular aminal formation are reported.

     

Synthesis and crystal structures of bimetallic hydrogen sulfates M I M II [H(SO4)2](H2O)2 (M I = K, Cs; M II = Zn, Mn) and selenate KMg[H(SeO4)2](H2O)2

Single crystals of acid salt hydrates M ^I{M ^II[H(XO₄)₂](H₂O)₂}, where M ^I, M ^II, and X are K, Zn, and S (I); K, Mn, and S (II); Cs, Mn, and S (III); or K, Mn, and Se (IV), respectively, were synthesized and studied by X-ray diffraction analysis. Compounds I–IV (space group $P\bar 1$ ) are isostructural to each other and to hydrate KMg[H(SO₄)₂](H₂O)₂ (V) studied earlier. Structures I–V, especially, the M ^I-O, M ^II-O, and X-O distances and the O?H?O (2.44–2.48 Å) and O_w-H?O (2.70–2.81 Å) hydrogen bonds, are discussed.     

Crystal structures of copper(II) nitrate,copper(II) chloride,and copper(II) perchlorate complexes with 2-formylpyridine semicarbazone

Compounds dinitrato(2-formylpyridinesemicarbazone)copper (I), dichloro(2-formylpyridinesemicarbazone) copper hemihydrate (II), and bis(2-formylpyridinesemicarbazone)copper(2+) perchlorate hydrate (III) are synthesized and their crystal structures are determined. In compounds I–III, the neutral 2-formylpyridine semicarbazone molecule (L) is tridentately attached to the copper atom via the N,N,O set of donor atoms. In compounds I and II, the Cu: L ratio is equal to 1: 1, whereas, in III, it is 1: 2. In complex I, the coordination sphere of the copper atom includes two nitrate ions with different structural functions in addition to the L ligand. The structure is built as a one-dimensional polymer in which the NO₃ bidentate group fulfills a bridging function. The coordination polyhedron of the copper(2+) atom can be considered a distorted tetragonal bipyramid (4 + 1 + 1). Compound II has an ionic structure in which the main element is the [CuLCl₂ · Cu(H₂O)LCl]⁺ dimer. In the dimer, the copper atoms are linked via one of the μ₂-bridging chlorine atoms. The coordination polyhedra of the central atoms of the Cu(H₂)LCl and CuLCl₂ complex fragments are tetragonal bipyramid and tetragonal pyramid, respectively. In compound III, the copper atom is octahedrally surrounded by two L ligands in the mer configuration.     

Syntheses,Structures and Luminescent Properties of Zinc(II) and Cadmium(II) Complexes With the Ditopic Ligand 1,3-Bis(imidazol-1-ylmethyl)benzene

Abstract  

Three new complexes, namely [Zn(mbix)(SO₄)]·CH₃OH (1), Cd(mbix)₂(NO₃)₂ (2) and [Cd(mbix)₂(H₂O)₂]·(NO₃)₂ (3), have been obtained by reactions of flexible bidentate ligand 1,3-bis(imidazol-1-ylmethyl)benzene (mbix) with corresponding zinc(II) and cadmium(II) salts. The structures of these complexes have been determined by the X-ray single crystal diffraction analysis. Complex 1 features a 2D wavy network with (4,4) topology. Complex 2 has a 2D grid network with left- and right-handed helical chains, while complex 3 exhibits twofold parallel interpenetration structure. The differences of three complexes demonstrate that the coordination geometry of metal ions and the ratio of reactants have a great impact on the structure of the supramolecular architectures. The luminescent properties of three complexes are also investigated.     

Structures of mixed-ligand Manganese(II) compounds [Mn(Heida)(Phen)]2 · 7H2O and [Mn2(Edta)(Phen)] · 4H2O

The crystal structures of [Mn(Heida)(Phen)]₂ · 7H₂O (I) and [Mn₂(Edta)(Phen)] · 4H2O (II) are studied by X-ray diffraction [R ₁ = 0.0375 (0.0283) and wR ₂ = 0.0954 (0.0662) for 5449 (3176) observed reflections in I (II), respectively]. Structure I contains mononuclear mixed-ligand complexes [Mn(Heida)(Phen)] and [Mn(Heida)(Phen)(H₂O)]. In structure II, the [Mn(Edta)]²⁻ anionic complexes and the [Mn(Phen)(H₂O)₂]²⁺ cationic complexes are linked by the bridging carboxyl groups into the tetramers with C ₂ symmetry. In both compounds, two independent Mn atoms have different coordination numbers (6 and 7). __________ Translated from Kristallografiya, Vol. 47, No. 2, 2002, pp. 280–285. Original Russian Text Copyright ? 2002 by Polyakova, Sergienko, Poznyak.     

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].     

Synthesis,Characterziation and SOD Activity of Manganese(II) Complexes with Aza-Macrocyclic Ligand

Abstract  

Two manganese(II) complexes, [Mn₂(L)(H₂O)₄]Cl₂·6H₂O(1) and [Mn₂L(NCS)₂(H₂O)₂]·3H₂O(2) (L is 1,2,4-triazolato)-4,12,17,25-tetramethyl-1,2,5,8,11,14,15,18,21,24-decaza-4,11,17,24-cyclohexaeicosatetraene) have been prepared by template synthesis method. They are characterized by elemental analysis and IR. Single-crystal X-ray analysis reveals that complex (1) crystallizes in space group P 2₁/c with a = 8.710(3), b = 14.720(5), c = 14.301(5) ?, α = 90, β = 105.801(14), γ = 90°. The complex [Mn₂(L)(H₂O)₄]Cl₂·6H₂O consists of two manganese(II) macrocyclic complexes in which two Mn(II) centers are linked by two triazolate units of the macrocyclic framework. Each manganese(II) ion is coordinated by five nitrogen atoms from the macrocycle and two oxygen atoms of the coordinated water. The manganese(II) center is in an approximately pentagonal-bipyramidal environment. The SOD activities of both complexes have also been investigated.     

Metal-betaine interactions. IV. Crystal structures of trans-tetraaquabis(betaine)nickel(II) nitrate and trans-diaquatetrakis(pyridine betaine)cobalt(II) bis[trichloro(pyridine betaine)cobaltate(II)]

Two transition metal(II) complexes of betaine (Me₃N⁺CH₂COO^–, designated as BET) and pyridine betaine (C₅H₅N⁺CH₂COO^–, pyBET) have been prepared and investigated by X-ray crystallography and infrared spectroscopy. [Ni(BET)₂(H₂O)₄] (NO₃)₂ (1), (R _F=0.054 for 2518 observed MoK data) comprises slightly distorted octahedral [Ni(BET)₂(H₂O)₄]²⁺ cations in which the Ni(II) atom is centrosymmetrically coordinated by four aqua ligands and twotrans-related unidentate BET ligands, and the uncoordinated carboxy oxygens form intramolecular hydrogen bonds with the aqua ligands. [Co(pyBET)₄(H₂O)₂]·2[Co(pyBET)Cl₃] (2) (R _F=0.029 for 4696 observed data) consists of discrete octahedral [Co(pyBET)₄(H₂O)₂]²⁺ cations and tetrahedral [Co(pyBET)Cl₃]^– anions. In the centrosymmetric cation each of the twotrans-related aqua ligands form a pair of intramolecular hydrogen bonds with the uncoordinated oxygen atoms of two unidentate pyBET ligands. In the anion the cobalt atom is coordinated by one unidentate pyBET ligand and three chloro ligands.     

Crystal and molecular structure of palladium(II), copper(II) and zinc(II) complexes of 1-methyl-3-(4-methyl)phenyltriazen-1-oxide

The structures of palladium(II), copper(II) and zinc(II) bis(chelates) of 1-methyl-3-(4-methyl)phenyltriazen-1-oxide have been determined by single-crystal X-ray methods. The crystals of [Pd(OMeN₃C₆H₄Me-4)₂] (I) are triclinic witha=7.410(3),b=7.806(3),c=8.371(2) Å, =65.80(2), =88.73(3), =81.04(3)°,Z=1, space group . The crystals of [Cu(OMeN₃C₆H₄Me-4)₂] (II) are monoclinic,a=14.934(5),b=10.111(4),c=11.762(3) Å, =96.00(2)°,Z=4, space group P2₁/c. The crystals of [Zn(OMeN₃C₆H₄Me-4)₂] (III) are triclinic witha=7.912(2),b=10.056(2),c=11.600(2) Å, =87.31(3), =74.96(3), =74.02(3)°,Z=2, space group . The structures of (I), (II), and (III) were solved to final values ofR=0.029, 0.043 and 0.034, respectively. A planar structure has been found for (I), (II) exhibits a tetrahedrally distorted square planar structure, whereas (III) is tetrahedral. The crystals of all three complexes are held by networks of stacking interactions.