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Dinuclear Structure (dinuclear + structure)
Selected AbstractsComplexes of the Bicyclic Multifunctional Sulfur-Nitrogen Ligand F3CCN5S3 with Co2+, Zn2+, Cu2+, and Cd,EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 17 2005Carsten Knapp Abstract The ability of the sulfur-nitrogen-carbon bicycle F3CCN5S3 to act as a donor towards transition metal cations has been investigated. F3CCN5S3 forms complexes with [M(SO2)2](AsF6)2 [M = Co, Cu, Zn, Cd] in the ratio 2:1 of the composition [M(F3CCN5S3)2(OSO)2(FAsF5)2] [M = Co (1), Zn (3)], [Cu(F3CCN5S3)2(,-F)(,-F2AsF4)]2 (4), and [Cd(F3CCN5S3)(,-F3CCN5S3)(,2 -F2AsF4)2]2 (5) in liquid sulfur dioxide. In the octahedral Co and Zn complexes F3CCN5S3 coordinates as a monodentate ligand through the bridging nitrogen atom N5, which carries the highest negative charge according to theoretical calculations. With Cu2+ a dinuclear structure with a central planar, four-membered Cu2F2 ring is formed, which has the shortest Cu···Cu distance of all structurally characterized Cu2F2 units. Similar to the Co and Zn complexes, F3CCN5S3 acts as a terminal monodentate ligand in the Cu compound. The reaction with the larger and softer Cd2+ cation results in a dinuclear complex that contains terminal and bridging F3CCN5S3 ligands. The bridging ligands coordinate through N5 and a nitrogen atom neighboring the carbon atom. In addition, a third weak bonding interaction between one fluorine atom of the trifluoromethyl substituent and the Cd2+ center is observed. The formation of the different structures and the versatile coordination modes of the F3CCN5S3 ligand are discussed. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source] Concomitant polymorphic behavior of di-,-thiocyanato-,2N:S;,2S:N -bis[bis(tri- p -fluorophenylphosphine-,P)silver(I)]ACTA CRYSTALLOGRAPHICA SECTION B, Issue 1 2010Bernard Omondi The structures of two polymorphs, both monoclinic P21/n [polymorph (I)] and P21/c [polymorph (II)], of di-,-thiocyanato-,2N:S;,2S:N -bis[bis(tri- p -fluorophenylphosphine-,P)silver(I)] complexes have been determined at 100,K. In both polymorphs the complex has a dinuclear structure where the silver(I) coordinates to two phosphine ligands and two bridging thiocyanate anions to form complexes with distorted tetrahedral geometry. Polymorph (I) has just one half of the [Ag2(SCN)2{P(4-FC6H4)3}4] molecule at (0, ½, 0) from the origin in the asymmetric unit. Polymorph (II) has one and a half molecules of [Ag2(SCN)2{P(4-FC6H4)3}4] in the asymmetric unit; the half molecule is situated at (0, 1, ½), while the full molecule is located at (1/3, ½, 1/3) from the origin. The Ag,P bond distances range from 2.4437,(4) to 2.4956,(7),Å in both polymorphs. The Ag,S distances are 2.5773,(7),Å in (I) and 2.5457,(5), 2.5576,(5) and 2.5576,(5),Å in (II). The full molecule in polymorph (II) has slightly shorter Ag,N bond distances [2.375,(1) and 2.367,(2),Å] compared with the half molecules in both polymorphs [2.409,(2),Å in (II) and 2.395,(2),Å in (I)]. The two polymorphs are compared using r.m.s. overlay calculations as well as half-normal probability plot analysis. [source] Ligand Reprogramming in Dinuclear Helicate Complexes: A Consequence of Allosteric or Electrostatic Effects?CHEMISTRY - A EUROPEAN JOURNAL, Issue 18 2007Abstract The ditopic ligand 6,6,-bis(4-methylthiazol-2-yl)-3,3,-([18]crown-6)-2,2,-bipyridine (L1) contains both a potentially tetradentate pyridyl-thiazole (py-tz) N - donor chain and an additional "external" crown ether binding site which spans the central 2,2,-bipyridine unit. In polar solvents (MeCN, MeNO2) this ligand forms complexes with ZnII, CdII, HgII and CuI ions via coordination of the N donors to the metal ion. Reaction with both HgII and CuI ions results in the self-assembly of dinuclear double-stranded helicate complexes. The ligands are partitioned by rotation about the central pypy bond, such that each can coordinate to both metals as a bis-bidentate donor ligand. With ZnII ions a single-stranded mononuclear species is formed in which one ligand coordinates the metal ion in a planar tetradentate fashion. Reaction with CdII ions gives rise to an equilibrium between both the dinuclear double-stranded helicate and the mononuclear species. These complexes can further coordinate s-block metal cations via the remote crown ether O - donor domains; a consequence of which are some remarkable changes in the binding modes of the N-donor domains. Reaction of the HgII - or CdII -containing helicate with either Ba2+ or Sr2+ ions effectively reprogrammes the ligand to form only the single-stranded heterobinuclear complexes [MM,(L1)]4+ (M=HgII, CdII; M,=Ba2+, Sr2+), where the transition and s-block cations reside in the N- and O-donor sites, respectively. In contrast, the same ions have only a minor structural impact on the ZnII species, which already exists as a single-stranded mononuclear complex. Similar reactions with the CdII system result in a shift in equilibrium towards the single-stranded species, the extent of which depends on the size and charge of the s-block cation in question. Reaction of the dicopper(I) double-stranded helicate with Ba2+ shows that the dinuclear structure still remains intact but the pitch length is significantly increased. [source] Synthesis and Structures of Lanthanide Complexes of N - p -Tolylsulfonylglycinate and 1,10-PhenanthrolineCHINESE JOURNAL OF CHEMISTRY, Issue 9 2005Man-Bo Zhang Abstract Three new lanthanide complexes with the formulae [Eu2(TsGly) 6(phen) 2(H2O) 2] (1), [Ln(TsGly) 2(phen) 2(H2O) 2]Cl·2H2O [Ln=Er (2a) and Yb (2b), TsGlyN - p -tolylsulfonylglycinate, phen1,10-phenanthroline] were synthesized. Crystallographic data for 1: monoclinic, P21/n, a=1.29791(16) nm, b&=1.9034(2) nm, c=1.7596(2) nm, ,=93.410(3) °, V=4.3394(9) nm3, Z=4, R1=0.0326, wR2=0.0771; and for 2b: triclinic, P1, a=1.2674(2) nm, b=1.4405(2) nm, c=1.4809(3) nm, ,=113.256(3) °, ,=108.253(3) °, ,=94.739(3) °, V=2.2922(7) nm3, Z2,R1=0.0292, w R2=0.0669. X-ray diffractional analysis reveals that compound 1 adopts dinuclear structure with fourfold bridging TsGly ligands between the Eu(III) centers, while compound 2b features an unusual mononuclear structure. [source] Lanthanide Complexes of Disulfoxide Ligands with Varied Configurations: Influence of Lanthanide Contraction on the Structures of the ComplexesEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 10 2005Jian-Rong Li Abstract Four new disulfoxide-LnIII complexes, [Ln(L)2(NO3)3]n {Ln = La (1), n = n; Ln = Gd (2), Dy (3) and Yb (4), n = 2}, have been prepared by the reaction of Ln(NO3)3·nH2O with meso -1,3-bis(ethylsulfinyl)propane (meso - L) in methanol/triethylorthoformate, and their solid-state structures were characterized by IR spectroscopy, elemental analyses and X-ray diffraction. Complex 1 is a 1D double-bridged chain in which the LaIII ions are ten-coordinate and the L ligands adopt both meso and rac configurations, and a bis-monodentate bridging coordination mode. While complexes 2,4 have isostructural dinuclear structures, in which the LnIII ions are nine-coordinate and the ligands show two types of coordination fashions and configurations: bis-monodentate bridging with a meso -configuration, and monodentate coordination with a rac -configuration. The structural differences between 1 and 2,4 indicate the influence of lanthanide contraction on the complex structures. In addition, a change in configuration of the ligand occurs when it reacts with metal ions. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source] | ||||||||||