Structural and Electrochemical Studies of Some Cobalt(III) Complexes of 2-Aminomethylbenzimidazole and 2-(N-Methylaminomethyl)benzimidazole

1997 ◽  
Vol 50 (10) ◽  
pp. 1009 ◽  
Author(s):  
Terence J. Cardwell ◽  
Alison J. Edwards ◽  
Richard M. Hartshorn ◽  
Rodney J. Holmes ◽  
W. David McFadyen

A number of mixed-ligand cobalt(III) complexes containing either the ligand 2-aminomethylbenzimidazole (ambi) or its N-methyl derivative, namely 2-(N-methylaminomethyl)benzimidazole (mambi), have been prepared in relatively low yield; in particular, the complexes [Co(ambi)(acac)2] Cl, [Co(ambi)(Clacac)2] Cl, K[Co(ambi)(ox)2],[Co(ambi)2(acac)] (ClO4)2, [Co(mambi)(acac)2] Cl and [Co(mambi)(Clacac)2 ]Cl (acac = acetylacetonate, Clacac = 3-chloroacetylacetonate, ox = oxalate). The reduction potentials of these complexes have been measured in order to assess whether molecules of this type could be potential redox-activated hypoxic cell selective anticancer agents. The complex [Co(ambi)(acac)2] Cl.4·1H2O was characterized by single-crystal X-ray crystallography: a 19·425(1), b 17·734(1), c 15·979(1) Å, β 117·52(1)˚, monoclinic, space group C 2/c (No. 15)

2014 ◽  
Vol 69 (7) ◽  
pp. 799-803 ◽  
Author(s):  
Kiran Gupta ◽  
Peter Mayer ◽  
Ashutosh Pandey

1A[Al(OiPr)3]4 was reacted at ambient temperature with 3-chloropentanedione (3-ClacacH) in 1 : 1 molar ratio in toluene, to obtain the mono-substituted product. However, the bis-substituted dinuclear tetrakis(3-chloropentanedionato)-di-m-isopropoxy-dialuminum(III) [Al(μ-OiPr)(3-Clacac)2]2 () was isolated in 46% yield upon aging of the reaction mixture at −10 °C. The supernatant upon aging yielded a crop of tris-3-chloroacetylacetonate Al(3-Clacac)3·H2O (1) in 13% yield. Complexes 1A (monoclinic, space group P21/c with Z = 2) and 1(cubic, space group P43n with Z = 8) were characterized by elemental analyses, NMR and IR spectroscopy and single-crystal X-ray crystallography.


2020 ◽  
Vol 49 (29) ◽  
pp. 9948-9952 ◽  
Author(s):  
Koh Sugamata ◽  
Chikaze Takagi ◽  
Keiko Awano ◽  
Teruyuki Iihama ◽  
Mao Minoura

Two mixed-ligand metal–organic frameworks using benzene-1,4-dihydroxamic acid and isonicotinic acid were synthesized and fully characterized by single-crystal X-ray crystallography as well as N2, H2, and CO2 gas-sorption measurements.


Author(s):  
Moussa Faye ◽  
Papa Aly Gaye ◽  
Mouhamadou Moustapha Sow ◽  
Moussa Dieng ◽  
Farba Bouyagui Tamboura ◽  
...  

The use of N'–(1–(pyridin–2–yl)ethylidene)nicotinohydrazide (HL) in lanthanide(III) chemistry has yielded one mononuclear and one dinuclear complexes. The 1:1 Nd(NO3)3.6H2O or Pr(CH3COO)3.6H2O/HL in methanol afforded the complexes [Nd (HL)2(NO3)2(H2O)2].(NO3) (1) and {[Pr(L)(h2–OOCCH3)(H2O)](h1:h2:m–OOCCH3)2[Pr (L)(h2–OOCCH3)(H2O)]} (2). The structures of the complexes were solved by single crystal X–ray crystallography. In the mononuclear complex, the Nd3+ atom is coordinated by two neutral molecules of ligand acting in tridentate fashion, two nitrate anions acting in bidentate manner and two coordinated water molecules yielding a twelve–coordinated Nd atom. In the complex (2) the Pr3+ atoms are doubly bridged by two acetates anions and each metal ion is coordinated by one tridentate monodeprotonated molecule ligand, one bidentate acetate group and one coordinated water molecule. Each Pr3+ atom is nine–coordinated with an environment best described as a tricapped prismatic geometry. Complex 1 crystallizes in the monoclinic space group C2/c with the following parameters: a = 22.7657(8) Å, b = 8.4276(3) Å, c = 18.0831(7) Å, b = 114.851(2)°, V = 3148.2(2) Å3, Z = 4, R1 = 0.032, wR2 = 0.098. Complex 2 crystallizes in the monoclinic space group P21/n with the following parameters: a = 11.5388(6) Å, b = 14.1087(8) Å, c = 12.2833(6) Å, b = 102.211(2)°, V = 1954.45(18) Å3, Z = 2, R1 = 0.029, wR2 = 0.066. The supramolecular structures are consolidated by multiple hydrogen bonds.


1995 ◽  
Vol 50 (7) ◽  
pp. 1018-1024 ◽  
Author(s):  
Axel Michalides ◽  
Dagmar Henschel ◽  
Armand Blaschette ◽  
Peter G. Jones

In a systematic search for supramolecular complexes involving all combinations of the cyclic polyethers 12-crown-4 (12C4), 15-crown-5 (15C 5), 18-crown-6 (18C 6) and dibenzo- 18-crown-6 (DB -18C6), and the geminal di- or trisulfones H2C(SO 2Me)2, H2C (SO2Et)2 and HC (SO2Me)3-n (SO2Et)n (n = 0 -3 ) , only the following four complexes could be isolated and unequivocally characterized by elemental analysis and 1H NMR spectroscopy: [(12C4){H2C (SO2Et)2}2] (3), [(18C6){H2C (S O2Me)2}] (4), [(DB -18C 6){H2C (SO2Et)2}] (5) and [(D B -18C 6)2{HC (SO2Me )(SO2Et)2}3] (6). The structure of 3 (triclinic, space group P1̄) consists of crystallographically centrosymmetric formula units, in which the disulfone molecules are bonded on each side of the ring by two C -H ··· O(crown) interactions originating from the central methylene group (H···O 213 pm) and from the methylene group of one EtSO2 moiety ( H ··· O 237 pm). Formula units related by translation are connected into parallel strands by a third type of reciprocal C -H ···O bond (H ···O 232 pm) between the second H atom of the central methylene group and a sulfonyl oxygen atom of the adjacent unit. The structure of 4 (monoclinic, space group C2/c) showed severe disorder of the crown ether and could not be refined satisfactorily. Compounds 5 and 6 crystallized as long and extremely thin fibres, indicative of linear-polymeric supramolecular structures; single crystals for X-ray crystallography were not available.


1983 ◽  
Vol 38 (4) ◽  
pp. 426-427 ◽  
Author(s):  
Arndt Simon ◽  
Karl Peters ◽  
Harry Hahn

Abstract The structure of the title compound has been determined by X-ray crystallography. The title compound is synthesized from the elements at 600 °C. Its crystal structure, derived from powder data [3] is refined by single crystal diffractometer data. The structure is trigonal (P3̅ml, α = 684.1(1), c = 724.4(1) pm); Pd2+ cations and PS43- anions form a network with an anti-Claudetite (AS2O3) type structure. The PS4 units are distinctly distorted from ideal tetrahedral symmetry. The Pd atoms have a planar environment of 4 S atoms.


2004 ◽  
Vol 68 (5) ◽  
pp. 757-767 ◽  
Author(s):  
T. Mihajlović ◽  
H. Effenberger

AbstractHydrothermal synthesis produced the new compound SrCo2(AsO4)(AsO3OH)(OH)(H2O). The compound belongs to the tsumcorite group (natural and synthetic compounds with the general formula M(1)M(2)2(XO4)2(H2O,OH)2; M(1)1+,2+,3+ = Na, K, Rb, Ag, NH4, Ca, Pb, Bi, Tl; M(2)2+,3+ = Al, Mn3+, Fe3+, Co, Ni, Cu, Zn; and X5+,6+ = P, As, V, S, Se, Mo). It represents (1) the first Sr member, (2) the until now unknown [7]-coordination for the M(1) position, (3) the first proof of (partially) protonated arsenate groups in this group of compounds, and (4) a new structure variant.The crystal structure of the title compound was determined using single-crystal X-ray diffraction data. The compound is monoclinic, space group P21/a, with a = 9.139(2), b = 12.829(3), c = 7.522(2) Å, β = 114.33(3)°, V = 803.6(3) Å3, Z = 4 [wR2 = 0.065 for 3530 unique reflections]. The hydrogen atoms were located experimentally.


2010 ◽  
Vol 2010 ◽  
pp. 1-10 ◽  
Author(s):  
Stergios Zanias ◽  
Giannis S. Papaefstathiou ◽  
Catherine P. Raptopoulou ◽  
Konstantinos T. Papazisis ◽  
Vasiliki Vala ◽  
...  

As part of our interest into the bioinorganic chemistry of gallium, gallium(III) complexes of the azole ligands 2,1,3-benzothiadiazole (btd), 1,2,3-benzotriazole (btaH), and 1-methyl-4,5-diphenylimidazole (L) have been isolated. Reaction of btaH or btd withGaBr3orGaCl3resulted in the mononuclear complexes[GaBr3(btaH)2](1) and[GaCl3(btd)2](2), respectively, while treatment ofGaCl3with L resulted in the anionic complex(LH)2[GaCl4](3). All three complexes were characterized by single-crystal X-ray crystallography and IR spectroscopy, while their antiproliferative activities were investigated against a series of human and mouse cancer cell lines.


1995 ◽  
Vol 48 (4) ◽  
pp. 793 ◽  
Author(s):  
LT Ellis ◽  
HM Er ◽  
TW Hambley

The electrochemical reduction and DNA binding have been studied for a series of platinum(IV) complexes with Cl-, OH-, and carboxylate anions as the axial ligands ; [Pt(en)Cl4], [Pt(en)Cl2(OH)2], and [Pt(en)Cl2(OC(O)R)2], R = CH3, CH2CH3, CH2CH2CH3. Cathodic reduction potentials vary by more than 650 mV with the tetrachloro complex reduced most readily and the dihydroxo least readily. The binding of the complexes correlates with the reduction potentials with the more readily reduced complexes binding more readily to DNA. The influence of the reducing agent glutathione on platinum binding to DNA was found to depend on whether it was added before or after Pt/DNA incubation. The results are consistent with octahedral platinum(IV) binding monofunctionally to DNA, and molecular modelling studies have been used to confirm that this is sterically feasible. The crystal structure of [Pt(en)Cl2(OC(O)CH3)2] has been determined by X-ray diffraction methods and refined to R = 0.028 (977 F). The crystals are monoclinic, space group C2/c, a 15.569(6), b 8.104(1), c 13.188(1) Ǻ, β 136.38(2)°.


2012 ◽  
Vol 16 (01) ◽  
pp. 154-162 ◽  
Author(s):  
Edwin W.Y. Wong ◽  
Daniel B. Leznoff

The reduction of magnesium phthalocyanine (MgPc) with 2.2 equivalents of potassium graphite in 1,2-dimethoxyethane (DME) gives [K2(DME)4]PcMg(OH)(1) in 67% yield. Compound 1 was structurally characterized using single crystal X-ray crystallography and was found to be a monomeric, heterometallic complex consisting of a μ3-OH ligand that bridges a [MgIIPc3-]- anion to two potassium cations solvated by four DME molecules. An absorption spectrum of 1 confirms the Pc ligand is singly reduced and has a 3–charge. The solid-state structure of 1 does not indicate breaking of the aromaticity of the Pc ligand. Compound 1 is only the second Pc3- complex and the first reduced MgPc to be isolated and structurally characterized.


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