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showing 10 items of 2189 documents
Organotin(IV) Complexes of Aromatic Acid Hydrazides: Preparation and Spectroscopic Studies
1999
Abstract The ability of aromatic acid hydrazides, RCONHNH, to act as bidentate chelating agents towards diorganotin(IV) dichlorides has been investigated. The structure of the complexes were deduced from IR, NMR and Mossbauer spectroscopic techniques in combination with analytical data. The R2SnCI2.L complexes have octahedral geometry where the tin atom is chelated with one ligand (via carbonyl oxygen and hydrazinic nitrogen atoms), two chlorine atoms are in equatorial positions while the R groups are in the axial positions.
Organometallic Complexes with Biological Molecules, VI. Diorganotin(IV) and Triorganotin(IV) Ampicillin and Methicillin Derivatives: Spectroscopic In…
1996
Derivatives of D(-)-α-aminobenzylpenicillin (ampicillin) and of 2,6-dimethoxyphenylpenicillin (methicillin) with diorgano- and triorgano-tin(IV) moieties have been synthesized. The stoichiometries of the compounds obtained were of the type R 2 SnCIL.H 2 O, R 3 SnCILNa.H 2 O [L=ampicillin or methicillin monoanion; R=Me, Bu, Ph] and R 2 Snampic 2 . 2H 2 O (ampic=ampicillin; R=Me, Bu, Ph). For R 2 SnCIL.H 2 O and R 3 SnCILNa.-H 2 O, infrared (IR) data suggest five-coordination around the tin(IV) atom; in R 2 Snampic 2 .2H 2 O six-coordination is most likely to occur. Thermogravimetric (TG) analysis excludes any involvement in the coordination of tin(IV) by water molecules, in any of the compou…
Syntheses, crystal structures and magnetic properties of new oxalato-, croconato- and squarato-containing copper(ii) complexesElectronic supplementar…
2003
The preparation and magnetic investigation of five mononuclear copper(II) complexes of formula [Cu(pyim)(C2O4)(H2O)]·2H2O (1), [Cu(pyim)(C4O4)(H2O)2]·2H2O (2), Cu(pyim)(C5O5)·2.5H2O (3), [Cu(H2bim)(C2O4)(H2O)]·H2O (4) and [Cu(bpz)(C5O5)(H2O)] (5) [pyim=2-(2-pyridyl)imidazole, H2bim=2,2′-biimidazole, bpz=2,2′-bipyrazine, C2O42−=dianion of oxalic acid, C4O42−=dianion of squaric acid and C5O52−=dianion of croconic acid] are reported. The crystal structures of 1, 2, 4 and 5 have been determined. The copper atom has a distorted square pyramidal geometry in this family of complexes: two nitrogen atoms from the bidentate nitrogen donor [pyim (1 and 2), H2bim (4) and bpz (5)] and two oxygen atoms e…
Synthesis and crystal structure of the low-spin iron(II) complex [Fe(bpz)3](ClO4)2·H2O (bpz=2,2′-bipyrazine)
2004
Abstract The crystal structure of the title compound [Fe(bpz) 3 ](ClO 4 ) 2 · H 2 O (bpz=2,2 ′ -bipyrazine) has been determined by a single crystal X-ray diffraction study at 293(2) K. The complex is monoclinic, P 2 1 / c , a =17.263(3), b =9.983(2), c =17.921(4) A, β =107.94(3)°, V =2938.3(10) A 3 , Z =4, R =0.073 and R w =0.118. The structure is made up of tris-chelated [Fe(bpz) 3 ] 2+ cations, uncoordinated perchlorate anions and crystallization water molecules. The iron atom exhibits a FeN 6 distorted octahedral geometry with average Fe–N bond length and N–Fe–N bidentate angle of 1.962(5) A and 81.6(2)°. The value of the Fe–N bond distance and that of the room temperature magnetic mome…
Synthesis crystal structure and magnetic properties of [Fe2(bpym)(C5O5)2(H2O)4]·2H2O and two polymorphs of [Fe2(bpym)(C4O4)2(H2O)6]·2H2O (bpym = 2,2′…
1998
Abstract Two dinuclear iron(II) complexes of formulae [Fe2(bpym)(C5O5)2(H2O)4]·2H2O (1) and [Fe2(bpym)(C4O4)2(H2O)6]·2H2O (2) (bpym = 2,2-bipyrimidine, C5O52 = dianion of croconic acid (4,5-dihydroxycylopent-4-ene-1,2,3-trione) and C4O42 = dianion of squaric acid (3,4-dihydroxycyclobut-3-ene-1,2-dione)) were prepared and their crystal structures (at 103 K) determined by X-ray diffraction methods. The structure of 1 consists of neutral centrosymmetric [Fe2(bpym)(C5O5)2(H2O)4] units and water molecules of crystallization which are linked by an extensive network of hydrogen bonds. The coordination geometry around each iron atom is that of a compressed octahedron with bpym nitrogen atoms and cr…
Synthesis, crystal structure and magnetic properties of [Cu(bipy)2(CH3COO)][Cu(bipy)2(Cr(C2O4)3)]·∼10.5H2O, the first compound containing the [Cr(C2O…
2001
Abstract The reaction between copper(II) acetate with 2,2′-bipyridine and K3[Cr(C2O4)3] leads to the novel salt [Cu(bipy)2(CH3COO)][Cu(bipy)2(Cr(C2O4)3)]·∼10.5H2O, 1 (bipy=2,2′-bipyridine). The crystal structure of 1 consists of mononuclear cationic species [Cu(bipy)2(CH3COO)]+ and heterobinuclear anionic units, [Cu(bipy)2(Cr(C2O4)3)]−. The tris-oxalato-chromium entity behaves as a monodentate ligand toward the copper(II) ion within the complex anion. The distance between Cr(III) and Cu(II) across the bridging oxalato group is 5.056(2) A. The copper(II) ions exhibit a distorted trigonal bipyramidal surrounding in both cationic and anionic species. The π–π stacking interaction between bipy l…
Titanium Complexes with a Linked Amido−Cyclopentadienyl Ligand and a Bidentate Organyl Group: Synthesis, Structure, and Ethene Polymerization Activity
1998
Titanium complexes containing a linked isopropyl- or benzylamido(tetramethylcyclopentadienyl) ligand C5Me4SiMe2NR (R = iPr, CH2Ph,) and one bidentate organyl group C6H4(CH2NMe2)-2, CH2C6H4(NMe2)-2, and {η5-C5H3(CH2NMe2)-2}Fe(η5-C5H5) were prepared by salt metathesis of the corresponding dichloro complex Ti(η5:η1-C5Me4SiMe2NR)Cl2 with the lithium organyl. Single crystal X-ray structural analysis of Ti(η5:η1-C5Me4SiMe2NCH2Ph)- {C6H4(CH2NMe2)-2}Cl and of Ti(η5:η1-C5Me4SiMe2NiPr){CH2C6H4(NMe2)-2}Cl revealed the presence of intramolecular coordination with square pyramidal geometry around titanium. In the ferrocenyl derivative Ti(η5:η1-C5Me4SiMe2NCH2Ph)[{η5-C5H3(CH2NMe2)-2}Fe(η5-C5H5)]Cl the NMe…
Organometallic complexes with biological molecules
2002
Novel triorganotin(IV) complexes of two beta-lactamic antibiotics, 6-[D-(-)-beta-amino-p-hydroxyphenyl-acetamido]penicillin (=amoxicillin) and 6-[D-(-)-alpha-aminobenzyl]penicillin (=ampicillin), have been synthesized and investigated both in solid and solution states. The complexes corresponded to the general formula R(3)Sn(IV)antib*H(2)O (R=Me, n-Bu, Ph; antib=amox=amoxicillinate or amp=ampicillinate). Structural investigations about configuration in the solid state have been carried out by interpreting experimental IR and 119Sn Mossbauer data. In particular, IR results suggested polymeric structures both for R(3)Sn(IV)amox.H(2)O and R(3)Sn(IV)amp*H(2)O. Moreover, both antibiotics appear …
Organometallic complexes with biological molecules. XI. Solid state and in vivo investigations of some diorganotin(IV)-chloramphenicol and cycloserin…
1998
Abstract Diorganotin(IV) derivatives of chloramphenicol, {=D-(-)threo-2,2-dichloro-N-[ β -hydroxy- α -(hydroxymethyl)- β -(4-nitrophenyl)ethyl]acetamide (=Hchloramph)}, and D-cycloserine, {=(R)-4-amino-3-isoxazolidone [=Hcyclos]} have been prepared. The stoichiometries of the obtained compounds were R 2 SnClantib and R 2 Snantib 2 (antib −1 =chloramph −1 , R=methyl and phenyl; antib −1 =cyclos −1 , R=methyl). The solid state configuration of the complexes was investigated by I.R. and Mossbauer spectroscopy, from which structural hypotheses were inferred. In particular, the experimental data suggested monomer structures both for R 2 Sn(IV)Clchloramph and R 2 Sn(IV)chloramph 2 , in which chlo…
Tin(IV) and organotin(IV) complexes containing mono or bidentate N-donor ligands
1998
Abstract A series of adducts of the type [(L # ) y R n SnX 4− n ]· z H 2 O (L # =1-methylimidazole, y =1 or 2, R=Me, Et, Bu n or Ph, n =1, 2 or 3, X=Cl, Br or I, z =0, 1/2 or 1) has been characterized in the solid state and in solution by analyses, spectral (IR, 119 Sn Mossbauer, and 1 H, 13 C and 119 Sn NMR) data and conductivity measurements. The molecular weight determinations and the NMR data indicate that these organotin(IV) complexes partly dissociate in chloroform and acetone solution. The donor L # interacts with [(CH 3 ) 3 SnNO 3 ], yielding the 2:1 ionic complex [(L # ) 2 (CH 3 ) 3 Sn]NO 3 . The derivative [(L # ) 2 (CH 3 ) 2 SnCl 2 ] reacts with NaClO 4 , AgNO 3 , NaBPh 4 and KSC…