Search tips
Search criteria

Results 1-8 (8)

Clipboard (0)

Select a Filter Below

more »
Year of Publication
Document Types
2.  Synthesis, X-Ray Structure, and Characterization of Catena-bis(benzoate)bis{N,N-bis(2-hydroxyethyl)glycinate}cadmium(II) 
The reaction of N, N-bis(2-hydroxyethyl)glycine (bicine; bicH3) with Cd(O2CPh)2 · 2H2O in MeOH yielded the polymeric compound [Cd2(O2CPh)2(bicH2)2]n(1). The complex crystallizes in the tetragonal space group P41212. The lattice constants are a = b = 12.737(5) and c = 18.288(7) Å. The compound contains chains of repeating {Cd2(O2CPh)2(bicH2)2} units. One CdII atom is coordinated by two carboxylate oxygen, four hydroxyl oxygen, and two nitrogen atoms from two symmetry-related 2.21111 (Harris notation) bicH2− ligands. The other CdII atom is coordinated by six carboxylate oxygen atoms, four from two bicH2− ligands and two from the monodentate benzoate groups. Each bicinate(-1) ligand chelates the 8-coordinate, square antiprismatic CdII atom through one carboxylate oxygen, the nitrogen, and both hydroxyl oxygen atoms and bridges the second, six-coordinate trigonal prismatic CdII center through its carboxylate oxygen atoms. Compound 1 is the first structurally characterized cadmium(II) complex containing any anionic form of bicine as ligand. IR data of 1 are discussed in terms of the coordination modes of the ligands and the known structure.
PMCID: PMC2952795  PMID: 20976297
3.  Zinc(II) and Nickel(II) Benzoate Complexes from the Use of 1-methyl-4,5-diphenylimidazole 
Two new complexes, [Zn(O2CPh)2(L)2]·2MeOH (1·2MeOH) and [Ni2(O2CPh))4(L)2]·2MeCN (2·2MeCN), have been synthesized and characterized by X-ray analysis in the course of an ongoing investigation of the MII/X−/L [MII = Co, Ni, Cu, Zn; X− = Cl−, Br−, I−, NCS−, NO3−, N3−, PhCO2−; L = 1-methyl-4,5-diphenylimidazole] reaction system, aiming at understanding and assessing the relative strength and the way in which the intermolecular interactions control the supramolecular organization of these compounds. In the mononuclear complex 1·2MeOH, the benzoate ion acts as a monodentate ligand resulting in a distorted tetrahedral N2O2 coordination environment. Complex 2·2MeCN exhibits a dinuclear paddle-wheel structure; each NiII has a square pyramidal NiNO4 chromophore with four benzoate oxygens in the basal plane and the pyridine-type nitrogen atom of one ligand L at the apex. The structure of 1·2MeOH is stabilized by intramolecular π-π interactions between aromatic rings of adjacent 4,5-diphenylimidazole moieties; it is a feature also evidenced in similar compounds of the type [MX2L2].
PMCID: PMC2927736  PMID: 20811497
4.  Use of the 2-Pyridinealdoxime/N,N′-Donor Ligand Combination in Cobalt(III) Chemistry: Synthesis and Characterization of Two Cationic Mononuclear Cobalt(III) Complexes 
The use of 2-pyridinealdoxime (paoH)/N,N′-donor ligand (L-L) “blend” in cobalt chemistry has afforded two cationic mononuclear cobalt(III) complexes of the general type [Co(pao)2(L-L)]+, where L-L = 1,10-phenanthroline (phen) and 2,2′-bipyridine (bpy). The CoCl2/paoH/L-L (1 : 2 : 1) reaction system in MeOH gives complexes [CoIII(pao)2(phen)]Cl·2H2O (1·2H2O) and [CoIII(pao)2(bpy)]Cl·1.5MeOH (2·1.5MeOH). The structures of the complexes were determined by single-crystal X-ray crystallography. The CoIII ions are six-coordinate, surrounded by three bidentate chelating ligands, that is, two pao− and one phen or bpy. The deprotonated oxygen atom of the pao− ligand remains uncoordinated and participates in hydrogen bonding with the solvate molecules. IR data of the complexes are discussed in terms of the nature of bonding and the known structures.
PMCID: PMC2913532  PMID: 20721276
5.  Mononuclear and Dinuclear Manganese(II) Complexes from the Use of Methyl(2-pyridyl)ketone Oxime 
The reactions of methyl(2-pyridyl)ketone oxime, (py)C(Me)NOH, with manganese(II) sulfate monohydrate have been investigated. The reaction between equimolar quantities of MnSO4 · H2O and (py)C(Me)NOH in H2O lead to the dinuclear complex [Mn2(SO4)2{(py)C(Me)NOH}4] · (py)C(Me)NOH, 1 · (py)C(Me)NOH, while employment of NaOMe as base affords the compound [Mn(HCO2)2{(py)C(Me)NOH}2] (2). The structures of both compounds have been determined by single crystal X-ray diffraction. In both complexes, the organic ligand chelates through its nitrogen atoms. The IR data are discussed in terms of the nature of bonding and the structures of the two complexes.
PMCID: PMC2910486  PMID: 20671965
6.  In Search for Titanocene Complexes with Improved Cytotoxic Activity: Synthesis, X-Ray Structure, and Spectroscopic Study of Bis(η5-cyclopentadienyl)difluorotitanium(IV) 
The 1 : 2 reaction of [Ti(η5-C5H5)2Cl2] and AgF in CHCl3/H2O yielded the fluoro analog [Ti(η5-C5H5)2F2] (1) in almost quantitative yield (C5H5 is the cyclopentadienyl group). The coordination about the TiIV atom formed by two fluoro ligands and the centroids of the cyclopentadienyl rings is distorted tetrahedral. The compound crystallizes in the orthorhombic space group C2cm. The lattice constants are a = 5.9055(4), b = 10.3021(5), c = 14.2619(9) Å, and α = β = γ = 90°. The complex has been characterized by elemental analyses and spectroscopic (IR, 1H NMR) data. A structural comparison of the four members of the [Ti(η5-C5H5)2X2] family of complexes (X = F, Cl, Br, I) is attempted.
PMCID: PMC2905951  PMID: 20689714
7.  The First Metal Complexes of 4,6-diamino-1-hydro-5-hydroxy-pyrimidine-2-thione: Preparation, Physical and Spectroscopic Studies, and Preliminary Antimicrobial Properties 
The new complexes [M2O5L2(H2O)2] · H2O (M = Mo, 1; M = W, 2), [RuL2(H2O)2] · H2O (3), [ML3] · xH2O (M = Rh, x = 2, 4; M = Ir, x = 1, 5), [RhL2(PPh3)2](ClO4) · 2H2O (6), [PdL2] · 2H2O (7), [PdL(phen)]Cl · H2O (8), [Re OL2(PPh3)]Cl (9) and [UO2L2] (10) are reported, where LH is 4,6-diamino-1-hydro-5-hydroxy-pyrimidine-2-thione. The complexes were characterized by elemental analyses, physical techniques (molar conductivity, room-temperature magnetic susceptibility), and spectroscopic (IR, Raman, UV/VIS/ligand field, NMR, mass) methods. The ligand L− is in its thione form and behaves as a bidentate chelate with the deprotonated (hydroxyl) oxygen and the nitrogen of one amino group as donor atoms. Oxobridged dinuclear (1, 2) and various mononuclear (3–10) structures are assigned for the complexes in the solid state. The metal ion coordination geometries are octahedral (1–6, 9, 10) or square planar (7, 8). The free ligand LH and complexes 1, 4, 7, and 8 were assayed in vitro for antimicrobial activity against two bacterial and two fungal cultures.
PMCID: PMC2659754  PMID: 19325921
8.  Synthesis, X-Ray Structure, and Characterization of a Complex Containing the Hexakis(urea)cobalt(II) Cation and Lattice Urea Molecules 
The 12: 1 reaction of urea (U) with CoI2 in EtOH yielded the “clathrate-coordination” compound [CoU6]I2·4U (1). The complex crystallizes in the monoclinic space group P21/c. The lattice constants are a = 9.844(4), b = 7.268(3), c = 24.12(1) Å, and β=98.12(1)∘. The crystal structure determination demonstrates the existence of octahedral [CoU6]2+ cations, I- counterions, and two different types (two U1 and two U2) of hydrogen-bonded, lattice urea molecules. The [CoU6]2+ cations and the U1 lattice molecules form two-dimensional hydrogen-bonded layers which are parallel to the ab plane. The I- anions are placed above and below each layer, and are hydrogen bonded both to U1 molecules and [CoU6]2+ cations. Each U2 molecule is connected to a [CoU6]2+ cation through an N–H⋯O hydrogen bond resulting in a three-dimensional network. Room temperature magnetic susceptibility and spectroscopic (solid-state UV/Vis, IR, Raman) data of 1 are discussed in terms of the nature of bonding and the known structure.
PMCID: PMC2235932  PMID: 18288263

Results 1-8 (8)