Crystal structure of [Mn2(III)(salpa)2Cl2(H2O)2] (H2salpa = 1-(salicylaldeneamino)-3-hydroxypropane)

The manganese complex, (Mn₂(III)(salpa)₂Cl₂(H₂O)₂], has been prepared and its structure determined using x-ray crystallography. The dimer is a di-₂-alkoxo complex which is a six-coordinate manganese dimer with unsupported alkoxide bridges and a rare example of a chloride- and water-containing manganese dimer. The complex crystallizes in the monoclinic space group P2₁/c with a = 9.315(5), b = 11.130(4), c = 11.637(5) Å, = 104.33(3)°, V = 1169.0(9) ų, and Z = 2. The structure comprises discrete binuclear clusters in which the metal atoms are bridged by two alkoxo oxygens of the salpa^2– ligands. The Mn—O and Mn—N distances are in good agreement with those found for other manganese(III) Schiff base complexes. The Mn—Cl and Mn—O3 distances are 2.585(2) and 2.371(2) Å, respectively, and the Mn ··· Mn distance is 3.001(1) Å. In the crystal, there are two types of hydrogen bonding between the H₂O molecule and the Cl atom with Cl ··· H(H₂O) distance of 2.33(6) (intramolecule: –1 + x, y, –1 + z) and 2.68(6) Å (intermolecule: –1 + x, 0.5–y, –0.5 + z).     

Structure of (1,2-diaminoethane) (1-[[2-[(2-aminoethyl)imino]propyl]thio]-2-propanone)nickel(II) nitrate

A single crystal X-ray investigation of the purple nickel (II) complex Ni[L(en)](NO₃)2, produced by condensation of 1,2-diaminoethane (en) with the thiodiketone S(CH₂COCH₃)2 in the presence of nickel (II) nitrate (L is NH₂(CH₂)₂N=C(CH₃)CH₂SCH₂COCH₃), shows that the metal ions are six coordinate. The new ligand L is tetradentate, with the N,N and S donor atoms arranged meridionally, and the coordination shell completed by the carbonyl oxygen atom of L and the nitrogen atoms of 1,2-diaminoethane. Metal-ligand bond distances are Ni-N: 2.08 av. (en), 2.10 and 2.05 (NH₂ and N=C respectively of L); Ni-O, 2.16; Ni-S, 2.45 Å. There is considerable angular distortion from regular octahedral values of the bond angles at nickel. The crystals are monoclinic,P2₁/c (No. 14),a=12.433(2),b=11.709(1),c=13.150(2) Å,=103.93(1)°,V _c=1858.2(4) ų. The structure was solved by the heavy-atom method and refined by full-matrix least squares to anR value of 0.055 for 3633 reflections.     

Synthesis and structural characterization of [Ni(Me2NCH2CH2CH2N=CHC6H4O)2]

The synthesis, properties, and X-ray crystal structure of a Ni(II) complex of the tridentate Schiff base ligand Me₂NCH₂CH₂CH₂N=CHC₆H₄OH(LH) are described. The complex crystallizes in the monoclinic space group P2₁/c, with a = 10.180(2), b = 15.169(3), c = 15.293(4) Å, = 106.69(2)°, and Z = 4. The Ni atom shows a distorted fac-octahedral geometry, with the two Ni—N(Me₂) bonds being significantly longer than the two Ni—N(imino) bonds, 2.284(9), 2.310(9) vs. 2.051(2), 2.055(2) Å.     

Crystal structure of a tetranuclear nickel (II) complex of a 24-membered Schiff base macrocyclic ligand

The tetranuclear nickel(II) complex of 24-membered Schiff base macrocyclic ligand has been prepared by template condensation of two molecules 2,6-diformyl-4-chlorophenol with two molecules 2,6-bis(aminomethyl)-4-methylphenol monohydrochloride in methanol solution in the presence of excess nickel(II) acetate and sodium acetate/ acetic acid. The tetranuclear nickel(II) complex contains neutral molecules of composition LNi₄(CH₃COO)₂(OH)(CH₃O H OCH₃), together with two molecules methanol in the lattice, and it possesses a monoclinic space group C2/c, with a = 21.5053(18) Å, b = 8.8782(7) Å, c = 25.374(2) Å, = 93.7830(10)°, and D _calc = 1.631 mg/m³ for Z = 8. The crystallographic data show that the macrocyclic ligand binds four nickel(II) ions at the corners of an approximate square with a ₄ hydroxo group bound equally to four metals.     

Redetermination of the structure of bis[chloro-2-(2-hydroxy-4,5-dimethylphenylazo)-5,5-dimethyl-4,5,6,7-tetrahydrobenzothiazol-7-on] copper(II) complex

The crystal structure of C₁₇H₁₈ClCuN₃O₂S (M = 854.78, monoclinic, P2₁/c, a = 8.316(2), b = 18.461(4), c = 11.774(2) Å, = 99.64(3)°, V = 1782.0(7) ų, Z = 4) is formed by dimeric molecules [C₁₇H₁₈ClCuN₃O₂S]₂ with two monomeric units linked together by two chlorine atoms. The Cu atom is coordinated by two chlorine atoms, an oxygen atom, the azo nitrogen atom attached to the benzene ring, and the nitrogen atom of the thiazole ring, in the form of a distorted tetragonal pyramid.     

Synthesis, crystal structure and properties of square-planar acetato{[(4-methylimidazol-5-yl)methylene]histamine} copper(II) perchlorate

The square-planar complex [Cu(MIMH)(CH₃CO₂)](ClO₄) (1) (MIMH = [(4-methylimidazol-5-yl)methylene]histamine) was prepared and structurally characterized. Complex 1 crystallizes in the monoclinic space group P2₁/n with a = 10.5331(10), b = 12.6177(10), c = 12.9773(10) Å, = 107.710(10)°, V = 1643.0(2) ų, and Z = 4. Single-crystal X-ray analysis reveals that the copper(II) atom in 1 has a distorted square-planar environment defined by three nitrogen atoms from the Schiff base ligand and one oxygen atom from the acetate group. The Cu—N bond lengths range from 1.950(3) to 2.015(3) Å and the Cu—O(1) bond length is 1.952(2) Å. The electronic spectra of 1 in aqueous solutions indicates that 1 forms adducts of square-pyramidal geometry with H₂O. Cyclic voltammetry of 1 in DMF solution shows that there is some degradation of 1 upon reduction.     

The synthesis and crystal structure of one novel ternary complex of 2,2′-bipyridine N-salicylidenetyrosinatocopper(II)

The crystal structure of copper(II)—salicylidene-aminoacidate Schiff base—nitrogen-donor chelating ligand, [Cu(sal-tyr)(bipy)] (sal-tyr: N-salicylidenetyrosinato; bipy: 2,2-bipyridine) which is obtained by means of one-step synthesis, is presented. It crystallizes in space group P2₁2₁2₁ with a = 9.0356(18) Å, b = 11.992(2) Å, c = 20.618(4) Å. The Cu^II ion is five coordinated by one oxygen atom of carboxylate, the imine nitrogen atom, and the hydroxyl oxygen atom of the salicylidene in the Schiff base anion as well as two nitrogen atoms of bipy, resulting in a seriously distorted square pyramid coordination polyhedron. The phenol group and the apical coordination bond Cu(1)–N(2) are in the same side of the Schiff base chelating plane which could be attributed to the intramolecular C–H s interaction between the H(17) of the bipy and the benzene ring of the phenol. The hydrogen bond between the hydroxyl hydrogen atom of the phenol group and the coordinated oxygen atom of the carboxylate from neighboring molecule is helpful to stabilize the crystal.     

Synthesis and crystal structure of Schiff base transition metal complex [Co(PMBP-smdtc)2]⋅2H2O

A cobalt(II) complex, [Co(PMBP-smdtc)₂]2H₂O, in which PMBP-smdtc is the l-phenyl-3-methyl-4-benzoyl-5-pyrazolone Schiff base of S-methyldithiocarbazate, has been synthesized and characterized by IR spectrum and single crystal X-ray diffraction. The crystal is monoclinic: space group C2/c, with a = 12.455(2) Å, b = 16.024(2) Å, c = 20.513(3) Å, = 101.18(1)°, V = 4016.3(10) ų, and Z = 4. The cobalt ion is octahedrally coordinated by two tridentate Schiff base ligands with ONS donor atoms. The molecules are bridged together by two water molecules through H-bond along b axis and one-dimensional indented chain structure is formed.     

Synthesis and crystal structure of a macrocyclic azidotetraamine copper(II) complex

The complex [Cu(L)N₃](H₂O)(ClO₄) (1) (L = 3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,0^1.18, 0^7.12]docosane) has been prepared and characterized by X-ray crystallography. 1 crystallizes in the monoclinic space group P2₁/c, with a = 8.907(5), b = 20.036(3), c = 14.773(2) Å, = 103.78(2)°, V = 2560.6(15) ų, and Z = 4. The coordination geometry around the Cu(II) ion is a distorted square-pyramidal with four nitrogen atoms of the macrocycle and one nitrogen atom of the axial azido group.     

Crystal structure of a macrocyclic tetraamine isocyanato zinc(II) complex

The complex, [Zn(L)(NCO)]Cl · 3H₂O (1) (L = 3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,0^1.18,0^7.12]docosane), has been synthesized and structurally characterized. 1 crystallizes in the monoclinic system, space group P2₁/n with a = 10.530(3), b = 9.315(2), c = 27.188(3) Å, = 92.58(1)°, V = 2664.1(9)ų, and Z = 4. The zinc atom is in a distorted squarepyramidal environment with the four nitrogen atoms of the macrocycle and one nitrogen atom of the isocyanate ligand.     

Synthesis and crystal structure of a nickel(II) complex involving imino nitroxide radicals

A new complex of formula [Ni(im2-py)₂(SCN)₂]CH₃OH (im2-py = 2-(2-pyridyl)-4,4,5,5-tetramethylimidazoline-1-oxyl) has been synthesized and the crystal structure determined by X-ray diffraction methods. The complex crystallizes in the monoclinic space group P2₁/n with a = 15.525(5) Å, b = 13.405(4) Å, c = 16.167(5) Å, = 113.324(5)°, V = 3089.6(16) ų, and Z = 4. The structure of this complex is mononuclear with the nickel(II) ion octahedrally coordinated and bound to the imino nitroxide radicals through the imino nitrogen atoms. The thiocyanate groups are coordinated to the metal by the nitrogen atoms.     

Two-dimensional nickel(II) tetraaza macrocyclic complex linked by hydrogen bonds

The complex [Ni(L)](PDC) 2H₂O (L = 3,14-dimethyl-2,6,13,17-tetraazatricyclo[16,4, 0^1.18,0^7.12]docosane; PDC = 3,5-pyrazoledicarboxylate) has been synthesized and characterized by X-ray crystallography. It crystallizes in the monoclinic system P2₁/c with a = 9.739(4) Å, b = 10.491(3) Å, c = 16.884(3) Å, = 97.17(2)°, V = 1711.5(8) ų, Z = 4. The coordination environment around the nickel(II) ion exhibits a slightly distorted square-plane with four secondary amines of the macrocycle. The title compound is interconnected to give a two-dimensional network through the hydrogen-bonding interactions.     

Crystal and molecular structure of tetrakis(N,N′-diallylthiourea)nickel(II) iodide

Summary The crystal structure of tetrakis(N,N-diallylthiourea)nickel(II) iodide [Ni(C₇H₁₂N₂S)₄I₂] has been determined by a three-dimensional X-ray analysis. FinalR, after anisotropic least-squares refinement, is 8·8%. The crystals are tetragonal (P4/n):a = 11·24(1),c = 15·43(1) Å,Z = 2. Ni(II) is on a 4-fold axis; the coordination around it is flattened pyramidal and involves four sulphur atoms from four diallylthiourea molecules (Ni-S = 2·221 Å). Ni(II) is out of the plane through the sulphur atoms by 0·40 Å. Two I^- ions lie on opposite sides with respect to the nickel atom along the 4-fold axis, at distances Ni...I(1) = 3·74 Å, Ni...I(2) = 6·64 Å. The orientation of the allylthiourea molecules is determined mainly by a hydrogen bond formed by one nitrogen (N(1)) with the iodine which is nearer to the nickel.The authors are indebted to Prof. C. Furlani who kindly supplied the crystals of the compound.     

Synthesis, properties, and X-ray structure of [Cu(dpa)Cl2] (dpa = di-(2-picolyl)amine)

The mono(dpa)copper(II) complex [Cu(dpa)Cl₂] (1) (dpa = di-(2-picolyl)amine) has been synthesized and structurally characterized. It crystallizes in the monoclinic system P2₁/n with a = 8.155(1), b = 12.560(1), c = 12.817(2) Å, = 91.64(2)°, V = 1312.3(2) ų, Z = 4. The copper atom is coordinated by three nitrogen atoms from the dpa ligand and two chlorides in a distorted square-pyramidal environment. Cyclic voltammetric data show that 1 undergoes the reversible one-electron oxidation to the Cu(III) and the reversible one-electron reduction to the Cu(I) state.     

A dinuclear cyano-bridged complex based on hexacyanoferrate(III) and samarium(III) nitrate: synthesis and crystal structure

A new complex, [Sm(DMF)₄(H₂O)₄Fe(CN)₆]·H₂O (DMF = N, N-dimethylformamide), has been synthesized and characterized by X-ray single crystal structure and thermogravimetric analyses. The complex crystallizes in the P2₁/n space group, with lattice parameters a = 17.583(4) Å, b = 8.870(2) Å, c = 19.845(6) Å, = 95.98(3)°, V = 3078(1) ų, D _x = 1.679 Mg m^–3, D _m = 1.65(1) Mg m^–3, Z = 4. The molecular structure shows that a cyano-bridged bimetallic structure is obtained. The Sm atom is coordinated by eight oxygen atoms of four water molecules and four DMF molecules and one nitrogen atom of the bridging cyanide ligand. The iron atom assumes approximately an octahedral environment surrounded by six CN ligands. The hydrate water molecule is hydrogen-bonded to one of the O atoms bound to Sm. Each terminal CN ligand of the Fe(CN) ₆ ^3– entity is hydrogen-bonded to some O atoms of water molecules. An infrared spectrum is also reported.     

Intramolecular hydrogen bonding and tautomerism in 1-[N-(4-bromophenyl)]aminomethylidene-2(1H) naphthalenone

1-[N-(4-bromophenyl)]aminomethylidene-2(1H)naphthalenone (C₁₇H₁₂NOBr) (1) was synthesized and its crystal structure was determined. Compound (1) is monoclinic, space group P2₁/n with a = 4.808(1) Å, b = 20.617(1) Å, c = 13.750(1) Å, = 93.004(1)°, V = 1361.11(3) ų, Z = 4, D_c = 1.592 g·cm^–3, (Mo K) = 3.014 mm^–1, R = 0.051 for 1013 reflections [I > 2(I)]. There is a strong intramolecular hydrogen bond of distance 2.544(2) Å between the hydroxyl oxygen atom and imine nitrogen atom, the hydrogen atom essentially being bonded to the nitrogen atom. The title molecule is not planar. X-ray crystal structure determination reveals the existence of the keto (or predominantly keto) tautomer in (1). Spectra of compound (1) were observed by IR and NMR, and UV–visible spectra of (1) were studied in different solvents and acidic media.     

Synthesis and X-ray structure of dichlorobis(8-(diphenylphosphinyl)quinoline)nickel(II)

Dichlorobis(8-(diphenylphosphinyl)quinoline)nickel(II) was formed in the reaction of 8-(diphenylphosphino)quinoline with nickel chloride in air. The title complex crystallized in P1 with the following cell dimensions: a = 8.5685(3) Å, b = 10.7736(2) Å, c = 13.4391(5) Å, and = 110.447(2)°, = 94.577(2)°; = 111.138(2)°, giving a volume of 1053.75(6) ų. The trans-dichlorobis(8-(diphenylphosphinyl)quinoline) nickel(II) adapts a central symmetric distorted octahedron. The structure is compared to other nickel(II) cation complexes, and possible reasons for the bonding states are discussed.     

Schiff bases and their complexes with metal ions. Part II. Structures of N-n-butyl-2-hydroxy-1-naphthaldimine and bis[N-n-pentyl-2-hydroxy-1-naphthaldiminato]nickel(II)

The Schiff base ligand (1), [C₁₅H₁₇NO] crystallizes in the monoclinic space group P2₁/c witha=10.054(3),b=10.313(3), c=13.173(4)Å, =107.42(4)°,V=1303.2(7)ų,Z=4,Dx=1.159 g cm^–3, and (MoK)=0.674 cm^–1. The C2-O[1.23(1)Å] and C3–C4 [1.33(2)Å] bond lengths are short, due to its quinoidal structure. In the Schiff base nickel complex (2), [Ni(C₁₆H₁₈NO)₂] the asymmetric unit is comprised of two half-complexes. It crystallizes in the triclinic space group witha=5.124(3),b=16.227(3),c=16.886(4)Å, =95.47(8), =96.00(1), =90.71(4)°,V=1389.6(9) ų,Z=2,Dx=1.289 g cm^–3, and (MoK) =12.1 cm^–1. The coordination of the Ni(II) ions are square planar with bond angles between 87.9(1) and 92.1(1)°. The Ni–O and Ni–N distances are 1.819(2), 1.922(2) and 1.823(2), 1.914(3)Å in these two complexes.     

Synthesis and crystal structure of bis(2-methylbenzimidazolium) tetrahalocuprate(II)

The crystal structures of 2-methylbenzimidazolium tetrahalocuprates (H2-mebz)₂[CuX₄] (X = Cl and Br) have been detemined. The chloride salt is monoclinic, P2₁/c, with a = 8.540(2) Å, b = 16.591(2) Å, c = 14.303(3) Å, and = 98.69(2)°. The bromide salt is also monoclinic, P2₁/c, with a = 8.316(3) Å, b = 17.436(3) Å, c = 14.747(3) Å, and = 98.82(3)°. Both the compounds contain discrete distorted tetrahedral CuX₄ ^2– anions and almost planar 2-methylbenzimidazolium cations. In the chloride salt, three chloride ions are involved in hydrogen bonding instead of two bromide ions in the bromide salt.     

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.