Search results for "Denticity"
showing 10 items of 376 documents
Thermal- and photo-induced spin crossover in the 1D coordination polymer [Fe(4-tBupy)3][Au(CN)2]2 (4-tBupy = 4-tert-butylpyridine)
2021
Reaction of the unidentate pyridine ligand containing a bulky t-butyl substituent with Fe2+ and [Au(CN)2]− affords a new type of spin crossover (SCO) coordination polymer in the 1D compound [Fe(4-tBupy)3][Au(CN)2]2⋅0.5H2O (1), which is formed by chains of Fe(II) complexes linked through bridging [Au(CN)2]− with three terminal 4-tBupy and one monodentate [Au(CN)2]− ligands completing the octahedral coordination around Fe(II). Longer reaction times led to the minor products [Fe(4-tBupy)2][Au(CN)2]2 (2), which presents a 2D structure more similar to that found in the other SCO compounds based on [Au(CN)2]−, and the 1D compound [Fe(4-tBupy)2(MeOH)][Au(CN)2]2 (3), in which one of the three termi…
Crystal and solution structures of di-n-butyltin(IV) complexes of 5-[(E)-2-(4-methoxyphenyl)-1-diazenyl]quinolin-8-ol and benzoic acid derivatives: E…
2009
Abstract Reactions of nBu2SnCl(L1) (1), where L1 = acid residue of 5-[(E)-2-(4-methoxyphenyl)-1-diazenyl]quinolin-8-ol, with various substituted benzoic acids in refluxing toluene, in the presence of triethylamine, yielded dimeric mixed ligand di-n-butyltin(IV) complexes of composition [nBu2Sn(L1)(L2–6)]2 where L2 = benzene carboxylate (2), L3 = 2-[(E)-2-(2-hydroxy-5-methylphenyl)-1-diazenyl]benzoate (3), L4 = 5-[(E)-2-(4-methylphenyl)-1-diazenyl]-2-hydroxybenzoate (4), L5 = 2-{(E)-4-hydroxy-3-[(E)-4-chlorophenyliminomethyl]-phenyldiazenyl}benzoate (5) and L6 = 2-[(E)-(3-formyl-4-hydroxyphenyl)-diazenyl]benzoate (6). All complexes (1–6) have been characterized by elemental analyses, IR, 1H,…
Synthesis and characterization of sulfonamides containing 8-aminoquinoline and their Ni(II) complexes. Crystalline structures of the Ni complexes
2002
Reaction between 8-aminoquinoline and benzenesulfonyl, toluene-4-sulfonyl and naphthalene-2-sulfonyl chlorides in a basic medium leads to the formation of the corresponding sulfonamides. Reaction of these sulfonamides with Ni(II) salts leads to the formation of the corresponding complexes, with a NiL 2 stoichiometry. Determination of the crystalline structure by X-ray diffraction shows an octahedral environment for the Ni(II) ions, sulfonamides acting as bidentate ligands and two solvent molecules completing the octahedral coordination. The spectroscopic and magnetic properties of these compounds are also discussed.
Synthesis of new polydentate oxalamide-based ligands as chiral catalysts for the enantioselective addition of diethylzinc to benzaldehyde
2006
New polydentate oxalamide-based ligands have been studied as chiral catalysts in the enantioselective addition of diethylzinc to benzaldehyde
Coordination properties of adenosine-5'-monophosphate and related ligands towards Me2Sn(IV)2+ in aqueous solution.
2002
Abstract The coordination of Me 2 Sn(IV) 2+ to adenosine-5′-monophosphate (AMP) and the related compounds d -ribose-5-phosphate (R5P), d -glucose-1-phosphate (G1P) and d -glucose-6-phosphate (G6P) in aqueous solution was investigated by means of potentiometric titration, and 1 H-, 31 P-NMR and Mossbauer spectroscopic methods in the pH range 2–11 ( I =0.1 M NaClO 4 , 298 K). The complex of AMP and Me 2 Sn(IV) 2+ precipitated at low pH was characterised by elemental analysis, FT-IR and Mossbauer spectroscopic methods. From a comparison of the p K values obtained in the presence and absence of metal ion and the stability constants for the different systems, the coordination of {N} is excluded,…
Homoleptic heavy alkaline Earth and europium triazenides.
2009
The sigma-bond metathesis reaction between PhSiH(3) and the heteroleptic metal pentafluorophenyl compounds [Dmp(Tph)N(3)MC(6)F(5)(thf)(n)] (Dmp = 2,6-Mes(2)C(6)H(3) with Mes = 2,4,6-Me(3)C(6)H(2); Tph = 2-TripC(6)H(4) with Trip = 2,4,6-(i)Pr(3)C(6)H(2); n = 1, 2; M = Sr, Ba, Eu) supported by sterically crowded, biphenyl- and terphenyl-substituented triazenido ligands afforded the first homoleptic stontium, barium, and europium triazenides [M{N(3)Dmp(Tph)}(2)] {M = Sr (2), Ba (4), Eu (5)}. Crystallization of 2 from an n-heptane/1,2-dimethoxyethane mixture gave the complex [Sr{N(3)Dmp(Tph)}(2)(dme)] (3). All new compounds have been characterized by (1)H and (13)C NMR spectroscopy (not 5), ele…
New cyclic tetranuclear copper(II) complexes containing quadrilateral cores: Synthesis, structure, spectroscopy and their interactions with DNA in aq…
2017
Abstract Three new cyclic tetranuclear copper(II) complexes, Tetrakis{3-[(2-pyridylmethyl)-amino]-propionato}(tetrachloro)tetracopper(II)methanolhydrate (1·CH3OH·H2O), Tetrakis{3-[(2-pyridylmethyl)-amino]-propionato}(tetrathiocyanato)tetracopper(II) (2) and Tetrakis{3-[(2-pyridylmethyl)-amino]-propionato}(tetraazido)tetracopper(II) (3) have been synthesized by exploiting the chelating ability and bridging potential of a carboxyamine functionalized tridentate ligand, HL (HL = 3-[(2-Pyridylmethyl)-amino]-propionic acid). Complexes 1, 2 and 3 have been synthesized by carrying out reaction of the ligand HL with stoichiometric amounts of CuCl2·2H2O, CuCl2·2H2O/NH4SCN, and CuCl2·2H2O/NaN3, respec…
Hydrogen-bond tuning of ferromagnetic interactions: synthesis, structure and magnetic properties of polynuclear copper(ii) complexes incorporating p-…
2006
The reaction of copper(II) hydroxide with 2,2'-bipyridine (bipy) (1 : 1) in alkaline aqueous solution (pH 14) at room temperature affords the alternating carbonate/hydroxo-bridged copper(II) polymeric chain compound {[Cu3(bipy)3(mu-OH)2(mu-CO3)2].11H2O}n, 1, as determined by single-crystal X-ray diffraction. The structure of 1 is built up from two similar centro-symmetric dinuclear [(bipy)Cu(mu-OH)]2 cores which link together via bridging carbonate groups to mononuclear [(bipy)Cu] fragments to form the chain. Interdigitation of adjacent chains through pi-pi interactions, which involve each bipy ligand, forms sheets that are separated by the water molecules of crystallisation. Variable-tempe…
Study of the interaction between [Cu(bipy)]2+ and oxalate in dimethyl sulfoxide. Crystal structure of [Cu2(bipy)2(H2O)2ox]SO4·[Cu(bipy)ox]
1991
Abstract A study of complex formation between [Cu(bipy)]2+ and ox2− (bipy and ox2− being 2,2′-bipyridyl and the dianion of oxalic acid), has been carried out by potentiometry in dimethyl sulfoxide solution. The constants of the equilibria and are log β110 = 11.165(1) and log β210 = 13.185(5) at 25 °C and 0.1 mol dm−3 tetra-n- butylammonium perchlorate. The high values of these constants are consistent with the symmetrical bidentate and bis-bidentate modes of oxalate in [Cu(bipy)ox] and [Cu2(bipy)2ox]2+ units, respectively, as shown by X-ray diffraction studies. Well-formed single crystals of [Cu2(bipy)2(H2O)2ox]SO4· [Cu(bipy)ox] were grown from aqueous solutions and characterized by X-ray d…
Oxalate and 2,2′-bipyrimidine as bis-chelating ligands in the honeycomb layered compound {[Fe2(bpym)(ox)2]·5H2O}n
2002
The novel two-dimensional iron(II) compound of formula {[Fe2(bpym)(ox)2]·5H2O}n (1) [bpym = 2,2′-bipyrimidine and ox = oxalate dianion] is obtained by reaction of oxalic acid, iron(II) chloride and 2,2′-bipyrimidine in aqueous solution. The structure of 1 is made up of oxalato-bridged iron(II) chains cross-linked by bischelating bpym affording a honeycomb lattice. Variable-temperature magnetic susceptibility data of 1 show the occurrence of relatively large antiferromagnetic interactions between the high spin iron(II) ions separated by more than 5.5 A through bridging bpym [Jbpym = −4.0(2) cm−1] and ox [Jox = ca. −7.8(2) cm−1] ligands. These values compare well with those obtained in the ir…