Transition metal(II) complexes of a biological buffer. Structural and spectroscopic study on Co(II), Ni(II), Cu(II), Zn(II), and Cd(II) complexes of N-[2-hydroxy-1,1-bis-(hydroxymethyl)ethyl]glycine

The structural and spectroscopic properties of complexes of N-[2-hydroxy-1,1-bis-(hydroxymethyl)ethyl]glycine (thmmg) with Co(II), Ni(II), Cu(II), Zn(II), and Cd(II) were investigated. The complex [Zn(thmmg)₂] crystallizes in the space groupP2₁/n, witha=8.796(2),b=9.050(3),c=9.926(2) Å,=97.35(1)° andZ=2; the copper(II) homolog is isomorphous. The complex [Ni(thmmg)₂]·6H₂O crystallizes in the space groupP2₁/n witha=8.432(8),b=8.495(2),c=15.967(1) Å,=95.57(2)° andZ=2; the cobalt(II) homolog is isomorphous. Ni(II) and Zn(II) complexes show an elongated octahedral coordination arising from two symmetry related amino acid molecules acting as a tridentate chelate through the amino nitrogen, one carboxylate oxygen, and one hydroxyl oxygen; the water molecules in the Ni(II) complex are not involved in metal coordination. The same ligand bonding mode may be suggested also for the Cu(II) and Co(II) complexes, while for Cd(II) only the nitrogen atom and the carboxylate oxygens seem to be involved in metal coordination.     

Structural and spectroscopic properties of N-benzenesulphonylglycine complexes with copper (II)

In this paper are reported structural and spectroscopic properties of (N-benzenesulphonylglycinato) triaquacopper (II) (complex I) and dipotassium bis (N-benzenesulphonylglycinato) cuprate (II) (complex II). The crystals of (I) are monoclinic, space groupP2₁/c,Z=4, with=12.736(4),b=10.292(3),c=10.402(3) Å,=109.41(2)° while those of complex (II) are orthorhombic, space groupPbca, witha=23.333(8),b=10.508(4),c=16.989(5) Å. In both complexes the aminoacid molecules act as bidentatevia carboxylic oxygen and the amide nitrogen atom; in (I) three water molecules complete the coordination to tetragonal pyramidal, while in (II) coordination is square planar, tetrahedrally distorted involving two ligand molecules. The structure (I) was refined to a finalR index of 0.0596 and (II) toR=0.0466.     

Structure of dichloroethanolaminecopper(II) and dibromoethanolaminecopper(II)

CuCl₂(NH₂CH₂CH₂OH) is monoclinic, space group C2/c, witha+11.092(2),b+10.012(2),c+6.401(1) Å, =121.71(1)°, andV=604.8(2)ų withZ+4. The structure was refined to a final value ofR+0.27 for 518 unique observed reflections with |F|>3. The ethanolamine and halide ions coordinate to the copper(II) ion forming a pseudoplanar four-coordinate monomeric CuCl₂L² complex (L²+bidentate ligand). The copper ion also interacts with the halides of neighboring complexes through the formation of semi-coordinate Cu-Cl linkages (2.926(1) Å) between oligomers. The copper thus attains a 4+2 elongated octahedral coordination geometry. In this space group, the ligand is statisticallydisordered The Cu-Cl distance is 2.267(1)Å while the Cu-N/O distances are 2.025(2)Å. The dibromide structure is isomorphous with the dichloride structure, with space group C2/c, anda+11.285(2),b+10.218(2),c+6.715(1) Å, =121.65(1)°, andV=659.2(2)ų.     

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.     

Crystal structure and single-crystal polarized spectrum of 1,4,7,10-tetraazadecanebis(N-methylimidazole)-nickel(II) perchlorate

The Ni(II) complex of 1,4,7,10-tetraazadecane (trien) andN-methylimidazole (Meim), [Ni(trien)(Meim)2](ClO₄)₂, crystallizes in the triclinic system witha=7.934(1),b=9.770(2),c=16.108(2) Å,=98.54(1),gb=97.16(1), and =98.10(1)°, The structure was refined by least-squares techniques to anR factor of 0.049 for 3729 observed reflections. The complexed nickel ion is octahedral. The trien ligand is bonded through its four nitrogens in the usual fashion, so that the terminal nitrogen atoms occupy;trans-positions on the octahedron. The remaining two coordination sites are filled by the Meim ligands. The Ni-N bond distances are normal, and range from 2.103(3) to 2.156(3) Å. The polarized single-crystal spectra are interpreted on the basis of an octahedral ligand field having a tetragonal distortion along the H₂N-Ni-NH₂ axis.     

Synthesis,spectroscopic characterization of thiosemicarbazone complexes of nickel(II) and X-ray structures of anisaldehyde thiosemicarbazone (ATSZH) and bis(tolualdehyde thiosemicarbazonato)nickel(II)

Complexes of nickel(II) with anisaldehyde (ATSZH), tolualdehyde (TTSZH), and vanillin (VTSZH) thiosemicarbazones have been synthesized and characterized by means of UV-Visible, I.R., Raman,¹H and¹³C NMR spectroscopy. The thiosemicarbazones have been found to exist in the thione form.¹H and¹³C NMR as well as electronic spectral data support a square planar structure for Ni(ATSZ)₂ and Ni(TTSZ)₂ complexes.¹H and¹³C NMR spectra indicate that the structure of Ni(VTSZ)₂ complex differs from the other two nickel(II) complexes and it may possibly consist of mixtures of isomers. The X-ray structures of Ni(TTSZ)₂ and ATSZH were determined: the nickel complex is monoclinic witha=26.412(6),b=12.135(3),c=6.888(1)Å,=95.41(5)°,Z=4,R=0.0647, space groupC2/c. The structure consists of discrete Ni(TTSZ)₂ molecules in which the metal, located on a symmetry centre, is N,S-chelated by two ligands forming two five-term chelate rings. The structure of ATSZH is also monoclinic:a=7.859(1),b=13.481(3),c=10.028(3) Å,=106.32(4)°,Z=4,R=0.0412, space groupP2₁/c. The molecules, connected by NO hydrogen bonds, reveal a considerable tilting of the aromatic ring in respect to the thiourea moiety if compared with the nickel structure.     

Crystal and molecular structure of bis(tetrathiafulvalene) bis(maleonitrile-1,2-dithiolato)nickelate(II)

The crystal and molecular structure of the title compound, C₂₀H₈N₄S₁₂Ni, is reported. Crystals are triclinic, space groupP¯1 (No. 2) withz=1 in a cell of dimensionsa=8;482(2),b=7.950(2),c=9.976(2) Å,=95.64(2),=98.60(2), and =87.65(2)°. The structure was solved by Fourier methods and refined by the method of least squares toR=0.033 for 2027 unique reflections. The Ni atom has an approximate square-planar configuration with Ni-S(1)=2.179(1), Ni-S(2)=2.175(1) Å, and the S(1)-Ni-S(2) bite angle of 91.89(4)°. The anions and the cations form a mixed stack (DAD-DAD-) along the diagonal of theab plane, showing the possibility of unusual electrical behavior.     

Palladium(II) and platinum(II) tetrakisthiourea dichloride bis(7-hydroxy-5-methyl[1,2,4]triazolo[1,5a]pyrimidine) dihydrate solvates

The title compounds palladium(II) and platinum(II) tetrakisthiourea dichloride bis(7-hydroxy-5-methyl[1,2,4]triazolo[1,5a]pyrimidine (Hmtpo)) dihydrate solvates, have been synthesized by reacting thecis-[MCl₂(Hmtpo)₂] (where M=Pt(II), Pd(II)) complexes with an excess of thiourea (tu) and the structure of the palladium compound was solved by X-ray diffraction. Crystals of [Pd(tu)₄]Cl₂·2Hmtpo·2H₂O are triclinic with space groupP and unit cell dimensionsa=7.972(1),b=9.049(1),c=11.808(2)Å, =88.20(1), =75.15(1), =76.54(1)^o. The cation [Pd(tu)₄]²⁺ is centrosymmetric involving four sulfur thiourea atoms in a near square planar environment. The triazolopyrimidine molecules, chloride anions and water molecules do not take part in the metal center coordination but interact by hydrogen bonding between them and the thiourea moieties. A comparison between powder diffraction data of palladium(II) and platinum(II) compounds clearly indicates that both compounds are isomorphous.     

Crystal and molecular structure of tetrapyridyl-copper(II)-bis-nitrato-bis-pyridine

The crystal and molecular structure of a pyridine complex of anhydrous copper(II)nitrate is described. The structure has been solved by vector search methods and refined by least-squares methods to R₁=0.049 [I>2(I)]. The complex lies on a twofold axis parallel toa, and two solvent pyridine molecules lie on twofold axes parallel toc. The copper atom is coordinated by four pyridyl groups and two monodentate NO₃ groups. Crystal data: C₃₀H₃₀N₈O₆Cu, orthorhombic, space group Pnna(52),a=14.446(7),b=12.154(5),c=16.881(4) Å,V=2964(2) ų,Z=4.     

The crystal structure of a N-(2-thiophenyl)-salicylaldiminopiperidino nickel(II) complex

The crystal and molecular structure of the title complex, C₁₈H₁₉N₂OSNi, has been determined by direct methods. The compound crystallizes in monoclinic crystal system witha=11.968(1),b=12.182(1),c=12.399(1) Å, =115.23(1)°, space group P2₁/n. Nickel is in a slightly distorted square-planar environment of two nitrogens [1.881(2) and 1.952(2) Å] and one oxygen [1.856(3) Å] and one sulphur [2.138(2) Å] atom. Ni is 0.005 Å out of the plane of its ligands.     

Aquadifluoro(1,10-phenanthroline)copper(II) dihydrate: X-ray crystal structure reveals strong hydrogen bonds between ligand fluoride and lattice water molecules

C₁₂H₁₄CuF₂N₂O₃,M=335.797, monoclinic, space groupP2₁/n,a=6.985(2),b=17.406(2),c=10.581(2) Å,=92.41(2)°,V=1285(1) ų,D _c =1.736 g cm^–3,Z=4,F(000)=684,(CuK)=27.0 cm^–1, =1.5418 Å,T=20°C, crystal dimensions=0.75×0.45×0.30 mm. The structure of the title compound shows it to be [Cu(phen)F₂(H₂O)]·2H₂O with pentacoordinate-square pyramidal Cu(II), short Cu-F bonds [1.890(4) and 1.891(4) Å], and short FH-O hydrogen bonds (ca. 2.68 Å) between the complex and lattice water molecule.     

Crystal and molecular structure of bromo-bis(bis-diphenylphosphino-ethylene)-nickel(II)-tetraphenylborate

The Ni(II) complex of the ligandcis-1,2[bis(diphenylphosphino)ethylene] (VPP), [Ni(VPP)₂Br]BPh₄, crystallizes in the orthorhombic space groupP2₁2₁,2, witha=25.971(6),b=24.508 (6),c=19.642(5) Å,Z=8. The structure was determined by the procedure DIRDIF from Cu K automatic diffractometer X-ray data and refined by block-diagonal least-squares toR=11% for 5572 reflections. A question on the space group assignment betweenP2₁2₁2 andP2₁2₁2₁ was resolved only after the complete structure had been determined. The detailed crystal and molecular structure is presented.     

Structural and spectroscopic study on imidazole-copper(II)-N-protected amino acid complexes. Crystal and molecular structure of tetrakis(imidazole)copper(II)bis(N-tosylvalinate)

A pink-red air-stable, crystalline compound of empirical formula [Cu(Im)₄(N-tsval)₂] (Im=imidazole; ts=4-toluenesulfonyl group, hereafter abbreviated as tosyl;N-tsval=N-tosylvalinate monoanion) was synthesized and characterized by means of structural and spectroscopic measurements. The crystal structure of the compound was determined from three-dimensional diffractometer data. The crystals are monoclinic, space groupC2/c, a=18.952 (5),b=12.372 (2),c=17.594 (3) Å,=93.77 (2)°,Z=4. The structure was solved by the heavy-atom method and refined through least-squares calculations toR=0.035 for 2284 observed reflections. The coordination about the copper atom is elongated octahedral, with four imidazole molecules as equatorial ligands and two sulfonic oxygens in axial positions.     

Crystal structure of bis(benzimidazolium) tetrabromocuprate(II)

Stable, dark-violet crystals of (C₇H₇N₂)₂CuBr₄ were obtained from an aqueous solution of CuBr₂, HBr, and benzimidazole. The crystal structure was determined by three-dimensional X-ray analysis. The crystals are monoclinic:C2/c, a=15.651(4),b=7.945(1),c=15.775(4) Å,=91.44(2)°,Z=4,V _c=1960.96 ų,D _x=2.105 g cm^–3. The structure was refined by full-matrix least squares to giveR=0.042 andR _w=0.048 for 1254 intensities above 3(I). The copper(II) ions are four-coordinated in the form of a distorted tetrahedron CuBr₄ ofC ₂ symmetry. Two different Cu-Br bond lengths are observed: Cu-Br(1)=2.426(2), Cu-Br(2)=2.330(2) Å. Only one flattened angle [Br(2)-Cu-Br(2)=132.71(9)°] in the CuBr₄ tetrahedron is noted. The angles Br(1)-Cu-Br(1)=108.83(7), Br(2)-Cu-Br(1)=99.92(5) and Br(2)-Cu-Br(1)=107.13(5)° have been found. Hydrogen bonds explain the deformation of the CuBr ₄ ^2– coordination polyhedron. The structure is compared with other CuX ₄ ^2– complexes.     

Crystal and molecular structures of two polymorphic forms of dimethyl-N-(2-ethylphenyl)-phosphoramidate (I) and dimethyl-N-(2,6-dimethylphenyl)-phosphoramidate (II)

The crystal structures of the phosphoric amides dimethyl-N-(2-ethylphenyl)-phosphoramidate (I) and dimethyl-N-(2,6-dimethylphenyl)-phosphoramidate (II) have been determined by direct methods and refined by full-matrix least squares. Compound (I) crystallizes in two polymorphic forms, both monoclinicP2₁/c, but with different cell parameters. Parameters for compound (I) are: FormA:a=10.878(5),b=8.890(4),c=25.11(1) Å,=92.18(2)°; FormB:a=7.071(4),b=17.059(9),c=10.221(5) Å,=97.07(2)°. Compound (II) is also monoclinicP2₁/c witha=8.453(4),b=14.231(7),c=10.283(5) Å,=108.95(2)°. Compound (I) exists as a hydrogen-bonded dimer, whereas compound (II) exists as a hydrogen-bonded polymeric species.     

A reinvestigation of the crystal structure of (4-aminobenzophenone)dichlorocuprate(II) hemiethanolate

The crystal structure of CuCl₂L·1/2 C₂H₅OH has been redetermined, where L=4-aminobenzophenone. C₁₄H₁₄Cl₂CuNO_1.5,M _r=354.5, monoclinic, P2₁/c,a=8.206(1),b=6.196(2),c=29.917 (7) Å, =92.91°,V=1521.8(6) ų,Z=4,D _x=1.55 g cm^–3, (MoK)=0.71069Å, =17.9 cm^–1,F(000)=720,T=295K. The 1984 unique reflections (20<45°), of which 1635 had |F_o|3 (F_o), refined to a finalR of 0.042 andwR=0.049 for the 3 data set. The structure is disordered at room temperature with the ethanol molecules, present at half-occupancy, coordinating to only one half of the Cu(II) ions. The structure is comprised of two types of chains which run parallel tob. One type of chain consists of stacks of CuCl₂L(C₂H₅OH) monomer units, which yield a 4+2 coordination geometry for each Cu atom in the chains. The second type of chains has stacks of binuclear Cu₂Cl₄N₂ species with a 4+1 coordination exhibited by each Cu. The location and orientation of the L ligands appear to be identical in the two stacks. Intermolecular hydrogen bonding between L ligands in adjacent stacks leave space for only one ethanol molecule per two ligands.     

Crystallographic and IR spectral study ofcis-bis(creatinine-N)dinitro platinum(II)

Acis-Pt(creat)₂(NO₂)₂ complex was synthesized stereoselectively in a high yield (65%) and characterized by IR spectral and X-ray diffraction analysis. Crystal data: Pt(C₄H₇N₃O)₂(NO₂)₂,M _r=767.55, monoclinic, space groupP2₁/n,a=9.736(1),b=13.433(1),c=12.098(1) Å,=110.55(1)°,V _c=1482(1) ų,Z=2,D _x=3.441 g cm^–3,(MoK)=0.71073 Å,=97.0 cm^–1,F(000)=1504,T=292 K,R=0.026 andR _w=0.028 for 2061 observed reflections with I>2(I). The structure consists of Pt(creat)₂(NO₂)₂ molecules disposed in general positions and joined by N-HO and N-HN hydrogen bonds. The platinum atom has square-planar PtN₄ coordination of twocis disposed pairs of nitro [Pt-N_av 2.023(7) Å] and creatinine [Pt-N(endo)_av 1.991(8) Å] ligands. The creatinine moieties are planar and tilted to the equatorial plane by ~80°.     

Structure of (chloranilato)bis(tri-n-butylphosphine)palladium(II)

(Chloranilato)bis(tri-n-butylphosphine)palladium(II), [Pd(C₆Cl₂O₄){P(C₄H₉)₃}₂] (chloranilic acid=2,5-dichloro-3,6-dihydroxy-p-benzoquinone): FW=718.02,P2₁/c,a=21.729(6),b=17.293(5),c=21.010(9) Å,=112.62(3)°,V=7287.42 ų,Z=8,D _c=1.309mg m^–3, Mo, =0.710730 Å,=0.76 mm^–1,F(000)=3008, finalR=0.087, 2594 observed reflections. Palladium is ligated by a distorted square planar P₂O₂ coordination sphere in the title compound. The two molecules per asymmetric unit differ in the arrangement of phosphine n-butyl chains, yielding two unique metal centers.     

Synthesis and crystal structure of a cobalt(II) complex with tris(1-pyrazolylmethyl)amine

The synthesis of a cobalt(II) complex of tris(1-pyrazolylmethyl)amine (amtp) is reported. The complex [Co(amtp)Cl](BPh₄) crystallizes in the space group P-1, with a = 8.979(2), b = 19.329(3), c = 20.251(3) Å, = 93.321(2), = 93.685(3), = 98.930(2)°, and Z = 4. The Co(II) atom is nearly tetrahedrally coordinated by three pyrazole N-atoms and one Cl^–. The tertiary amine N-atom of amtp is only weakly coordinated to Co(II) atom at a Co—N(amine) distance of ca 2.40 Å.     

Crystal and molecular structure oftrans-dichlorobis(N-propylimidazole)palladium(II)

The crystal structure of Pd(N-PropIm)₂Cl₂ has been determined from X-ray data collected by counter methods. The compound crystallizes in the monoclinic space groupP2₁/n with four molecules per unit cell, the dimensions of which area=14.554(5),b=8.204(2),c=14.860(3) Å,=115.63(2)°. Full-matrix least-squares refinement gave a final R value of 0.0263 for 1913 independent observed reflections. The Pd atom is four-coordinated and is surrounded in atrans square planar fashion by two N atoms of the imidazole groups and by two Cl ions.