Search results for "bond"
showing 10 items of 3527 documents
Synthesis, properties and crystal structure of bis(metiamide)bis(isothiocyanato)nickel(II)
1991
Abstract The crystal structure of Ni(metiamide)2(NCS)2 was determined by X-ray diffraction methods. Unlike cimetidine, which is a tridentate ligand, metiamide (C9H16N4S2): N-Methyl-N-[2-{(5-methylimidazol-4-yl)methylthio}ethyl]thiourea (which also possesses three potential donor sites) is bidentate, coordinated to the nickel atom through N(imidazole) and S(thioether) atoms. The S(thiourea) atom does not take part in the coordination; instead, the isothiocyanate ion is coordinated through nitrogen to the metal atom. The nickel atom lies on a centre of symmetry in an elongated octahedral environment: the nitrogen atoms occupy equatorial positions (NiN = 2.04 and 2.06 A) and S(thioether) atom…
[Mn2(bipym)(H2O)8]4+and [Fe(bipy)(CN)4]−as building blocks in designing novel bipym- and cyanide-bridged heterobimetallic complexes (bipym = 2,2′-bip…
2002
Two new cyano complexes, K[Fe(bipy)(CN)4]·H2O (1) and (μ-bipym)[Mn(H2O)3{Fe(bipy)(CN)4}]2[Fe(bipy)(CN)4]2·12H2O (2), have been synthesised and their structures determined by single-crystal X-ray diffraction. Complex 1 is made up of mononuclear [Fe(bipy)(CN)4]− anions, potassium cations and water molecules of crystallization. The iron(III) is six-coordinated, being surrounded by two nitrogen atoms of a chelating bipy and four carbon atoms of four cyanide groups [Fe–N and Fe–C 1.991(3)–1.990(3) and 1.958(5)–1.914(5) A, respectively]. Complex 2 consists of centrosymmetric tetranuclear (μ-bipym)[Fe(H2O)3{Fe(bipy)(CN)4}]22+ cations, [Fe(bipy)(CN)4]− anions and water molecules of crystallization.…
The synthesis and structural characterization of some triorganotin(IV) complexes of 2-{[(E)-1-(2-hydroxyaryl)alkylidene]amino}acetic acid. Crystal an…
2002
Abstract Triorganotin(IV) derivatives of 2-{[(E)-1-(2-hydroxyaryl)alkylidene]amino}acetic acid have been synthesized and characterized by 1H, 13C, 119Sn-NMR, 119Sn Mossbauer and IR spectroscopic techniques in combination with elemental analyses. The crystal structures of triphenyltin 2-{[(E)-1-(2-hydroxyphenyl)methylidene]amino}acetate and trimethyltin 2-{[(E)-1-(2-hydroxyphenyl)ethylidene]amino}acetate are reported. The X-ray structures reveal that the complexes adopt a polymeric trans-O2SnC3 trigonal bipyramidal configuration with the R groups in the equatorial positions and the axial locations occupied by a carboxylate oxygen from the ligand and the phenolic oxygen of the ligand on an ad…
Dynamic chemical devices: photoinduced electron transfer and its ion-triggered switching in nanomechanical butterfly-type bis(porphyrin)terpyridines.
2005
A series of butterfly-type molecular constructs has been prepared in good yield by using a double Stille coupling synthetic protocol. They are composed of a terpyridine (terpy) scaffold and two wings composed of appended porphyrins that are capable of switching from an extended W geometry to a compact U geometry upon cation coordination of the terpy unit. The porphyrin moieties exist in the constructs either as free bases or they can be sequentially metallated, thus giving rise to wings of different "colours". Stationary and time-resolved emission studies of the HZn, ZnAu and Zn2Au constructs show that the electronic properties are strongly dependent on the geometry. In the extended W confo…
Hydrogen and Halogen Bond Mediated Coordination Polymers of Chloro-Substituted Pyrazin-2-Amine Copper(I) Bromide Complexes
2020
A new class of six mono- (1
Ni(II) and Zn(II) complexes with cinoxacin. Synthesis and characterization of M(Cx)2(DMSO)n(H2O)m (n=0, 2; m=2, 4). Crystal structures of [M(Cx)2(DMS…
1993
Abstract New metal complexes of cinoxacin (HCx=1-ethyl-l,4-dihydro-4-oxo(1,3)dioxolo(4,5-g)cinnoline-3-carboxylic acid) were synthesized, isolated as [Zn(Cx)2(DMSO)2]·4H2O, [Ni(Cx)2(DMSO)2]·4H2O, Zn(Cx)2·4H20 and Ni(Cx)2·2H2O, and characterized by elemental analysis, TG studies, IR and UVVis spectroscopic techniques. The crystal and molecular structures of the complexes [M(Cx)2(DMSO)2]·4H2O (M=Zn(II), Ni(II)) have been determined by X-ray structure analysis. The crystals of [Zn(Cx)2(DMSO)2]·4H2O are triclinic, space group P 1 with unit cell dimensions a=8.950(4), b=9.168(5), c=11.650(6) A, α=69.06(1), β=82.05(1), γ=75.63(1)°, V=863.6(8) A3; [Ni(Cx)2(DMSO)2]·4H20 is monoclinic, space group …
New coordination polymer based on a triply bridged dicarboxylate ligand: Synthesis, structure, and magnetic properties of the adipato complex [Cu4(bp…
2007
International audience; One-pot reaction of copper(II) chloride dihydrate CuCl2 · 2H2O with 2,2′-bipyridyl (bpy = C10H8N2) in the presence of sodium adipate Na2adip (adip2− = [O2C(CH2)4CO2]2−) and potassium 1,1,3,3-tetracyano-2-ethoxypropenide (tcnoet− = [(NC)2CC(OEt)C(CN)2]−) gives the new compound [Cu4(bpy)4(adip)3](tcnoet)2 · 2H2O (1), which was characterized by single crystal X-ray diffraction analysis. The Cu(II) metal ion presents an elongated square pyramidal CuN2O3 environment, with an oxygen atom in apical position and a base plane involving almost equivalent bond lengths. The structure can be described as a pseudo dinuclear species in which two Cu(bpy) units are triply bridged by …
[Cr(bpym)(C2O4)2]− in designing heterometallic complexes. Crystal structures and magnetic properties of PPh4[Cr(bpym)(C2O4)2]·H2O and [Ag(bpym)][Cr(C…
2002
Abstract The preparation, crystal structure and magnetic properties of PPh 4 [Cr(bpym)(C 2 O 4 ) 2 ]·H 2 O ( 1 ) and [Ag(bpym)][Cr(C 2 O 4 ) 2 (H 2 O) 2 ]·2H 2 O ( 2 ) (C 2 O 4 2− =oxalate dianion, bpym=2,2′-bipyrimidine and PPh 4 + =tetraphenylphosphonium cation) are described. The structure of 1 is made up of discrete (2,2′-bipyrimidine)bis(oxalato)chromate(III) anions, teraphenylphosphonium cations and uncoordinated water molecules. The structure of 2 consists chains of univalent silver cations bridged by bis-chelating 2,2′-bypyrimidine, cis -diaquabis(oxalato)chromate(III) anions and crystallisation water molecules. The chromium atom in 1 and 2 has a slightly distorted octahedral geom…
4,2-Ribbon like ferromagnetic cyano-bridged FeIII2NiII chains: a magneto-structural study
2007
The low-spin iron(III) complex AsPh(4)[Fe(III)(bpy)(CN)(4)].CH(3)CN (1) [AsPh(4) = tetraphenylarsonium cation] and the heterobimetallic chains [{Fe(III)(L)(CN)(4)}(2)Ni(II)(H(2)O)(2)].4H(2)O with L = bpy (2) and phen (3) [bpy = 2,2'-bipyridine and phen = 1,10-phenanthroline] have been prepared and their structures determined by X-ray diffraction methods. The structure of 1 consists of mononuclear [Fe(bpy)(CN)(4)](-) anions, tetraphenylarsonium cations and acetonitrile molecules of crystallization. The iron(III) is hexacoordinated with two nitrogen atoms of the bidentate bpy and four carbon atoms of four terminal cyanide groups building a distorted octahedral surrounding around the metal ato…
Complexes of (CH3)2AuIII: synthesis, PMR and IR spectra
1975
Abstract The syntheses and reactivity of dimethylgold(III) complexes with multidentate ligands as TRIPHOS (i.e., 1,1,1-tris(diphenylphosphinomethyl)ethane) and TREN (i.e. 2,2′,2″-triaminotriethylamine) have been examined. I.r. spectra for the compounds in the solid state, conductivity and PMR data for solutions, lead to the assignment of an ionic formula [CH 3 ) 2 Au TRIPHOS] + [(CH 3 ) 2 AuCl 2 ] − where the gold(III) atoms are presumably four-coordinate. The complex (CH 3 ) 2 AuCl TREN in DMSO solution undergoes a reductive elimination reaction, as found for analogous dimethylgold(III) derivatives.