Interaction of Metal Ions with 7-Deaza-8-aza-and 8-Aza-purines Preparation and X-Ray Structural Analysis of Copper(II) Complexes

1987 ◽  
Vol 42 (2) ◽  
pp. 195-202 ◽  
Author(s):  
W. S. Sheldrick ◽  
P. Bell

Abstract The reaction of 8-aza-and 7-deaza-8-aza-purines with Cu2+ cations in acid solution has been studied. At a pH value of 2, the 8-azaadenine complex [Cu(H2O)4(AAdH)2](NO3)2 (1), which displays Cu-N9 coordination, may be isolated from solution. The reaction of CuCl2 with 8-aza-hypoxanthine in concentrated HCl solution leads to ring opening at C2 of the azapurine with subsequent formation of dichlorobis[(5-amino-4-carboxamide)[1 - 3]triazole] copper(II) dihydrate 2, in which the triazole ligands display a chelating function, coordinating the metal via N7 and O6. The results for 1 and 2 suggest that copper coordination of the azapurine base is not a prerequisite for opening of the pyrimidine ring. Respectively N9-and N8-coordinated complexes [CUCl3(AllH3)]n 3 and [CuCl2(H2O)(MAllH)]n (4) of allopurinol (AllH2) and 9-methylallopurinol (MAllH) may be prepared by the reaction of CuCl2 with the respective bases in HCl solution. In contrast, with the analogous 1-methyl-4-aminopyrazolo[3,4-d]pyrimidine MAPP, only the salt (MAPPH)4(CU2Cl8) (5) could be isolated under similar conditions, indicating that N8 is less attractive as a binding site in this 7-deaza-8-azaadenine derivative. The structures of 1-5 have been established by X-ray structural analysis. A distorted octahedral [4+2]geometry is found for the copper atoms in 1 and 2. Chlorine bridged polymeric chain structures are adopted by the complexes 3 and 4. An intermediate coordination geometry between trigonal bipyramidal and square-pyramidal is observed for the metal atoms in 3, a distorted square-pyramidal geometry in 4.

1995 ◽  
Vol 73 (1) ◽  
pp. 95-99 ◽  
Author(s):  
Frank E. Smith ◽  
Rosemary C. Hynes ◽  
John Tierney ◽  
Ying Z. Zhang ◽  
George Eng

The title compound was synthesized as part of an effort to produce a more effective fungicide to combat Dutch Elm Disease (DED), which is caused by the fungus Ceratocystisulmi. A full X-ray structural analysis of the 1:1 adduct has been carried out and the results are reported along with the Mössbauer data for the compound. The crystals are monoclinic, space group P21/a with a = 19.240(3) Å, b = 9.1463(24) Å, c = 19.3512(24) Å, β = 118.874(8)°, V = 2982.0(10) Å3, z = 4, and Dcalc = 1.427 Mg m−3. The final discrepancy factors are RF = 0.056 and Rw = 0.058 for 1915 significant reflections. The QS and IS values in the Mössbauer spectrum of the complex are 3.08 mm s−1 and 1.28 mm s−1, respectively. The 2,3-diphenylthiazolidin-4-one behaves as a monodentate ligand and coordinates to the tin through the oxygen atom. The complex exhibits a trigonal bipyramidal configuration with the three phenyl groups in equatorial positions and the chloride and ligand oxygen occupying the apical sites. Keywords: triorganotin, fungicide, Dutch Elm Disease, thiazolidin-4-one.


1992 ◽  
Vol 47 (3) ◽  
pp. 301-304 ◽  
Author(s):  
Stefan Vogler ◽  
Kurt Dehnicke

The title compound has been prepared by the reaction o f [WCl4(NSeCl)]2 with PPh4Cl in CH2Cl2 solution. It forms red crystals, which were characterized by an X-ray structure determination. Space group P21/c, Z = 4, 3856 observed unique reflections, R = 0.073. Lattice dimensions at 25 °C: a = 2266.0(5), b = 1121.0(2), c = 2013.0(4) pm, β = 109.66(3)°. The structure consists o f PPh4+ ions and anions [WCl5(NSeCl2)]2-, in which the tungsten atom is surrounded in a distorted octahedral way by five chlorine atoms and by the nitrogen atom of the (NSeCl2)3- ligand. The W = N = SeCl2 group is characterized by WN and SeN double bonds; the selenium atom has a pseudo trigonal-bipyramidal coordination with the N atom and two lone pairs in equatorial and the chlorine atoms in axial positions.


1995 ◽  
Vol 50 (4) ◽  
pp. 642-648 ◽  
Author(s):  
Rolf W. Saalfrank ◽  
Klaus Schobert ◽  
Stefan Trümmer ◽  
Alexander Wolski

The new bistetrazole 13 has been obtained by subsequent formation of the two heterocyclic units. In methanolic solution 13 reacts with zinc(II) acetate to yield the pseudo-meso-1 D-coordination polymer [ZnL2(MeOH)]n (n = ∞) 14. The structure of 14 was established by single crystal X-ray diffraction. The generation of the polymeric chain 14 is understandable, if intermediate formation of coordinatively unsaturated zinc(II) buildingblocks (Δ)-15 and (Λ)-15 is assumed. Alternating linkage of the self-complementary chiral monomers 15, across one cyanofunction each, leads to 14 with zinc being essentially octahedrally coordinated. Compared with polymeric compounds of similar bridging ligands, the Zn ··· N≡C-distance in 14 (225,7 pm) is short.


1991 ◽  
Vol 46 (5) ◽  
pp. 639-646 ◽  
Author(s):  
W. S. Sheldrick ◽  
C. Martin

The phenyliodoantimonates(III) [Et4N][Ph2SbI2] (1), [Et4N]2[Ph2Sb2I6] (2) and [Hpy]3[Ph2Sb2I7] (3) have been prepared and their structures established by X-ray structural analysis. The anion [Ph2SbI2]⁻ displays a ψ-trigonal bipyramidal structure with axial Sb–I distances of 2.925(1) and 3.109(1) A. In the dimeric anions [Ph2Sb2I6]2- and [Ph2Sb2I7]3- the antimony atoms exhibit ψ-octahedral geometries. As observed for [Ph2SbI2]⁻, terminal Sb–I bonds in trans-position to one another display significantly different lengths. The anion [Ph2Sb2I7]3- displays Ci- symmetry with a bridging iodine atom at the crystallographic centre of symmetry. Long Sb—I distances of 3.404(1) A are observed to this atom. A structural correlation of opposite Sb–X distances (X = Cl, Br, I) in linear three centre X–Sb ··· X interactions is presented. The sum of the bond valences in iodoantimonates(III) is a minimum for symmetrical I–Sb–I three centre bonds, reflecting thereby the antibonding influence of the Sb 5 s-orbital. This influence is considerably smaller for bromoantimonates(III) and may be effectively neglected for chloroantimonates(III).


1983 ◽  
Vol 36 (1) ◽  
pp. 183 ◽  
Author(s):  
EJ O'Reilly ◽  
G Smith ◽  
CHL Kennard ◽  
AH White

The crystal structures of two copper(II) complexes of the herbicide Picloram (4-amino-3,5,6-trichloro- pyridine-2-carboxylic acid) have been determined by single-crystal X-ray diffractometry. Bis(4-amino- 3,5,6-trichloropyridine-2-carboxylato)aquacopper(II) dihydrate (1) is monoclinic, space group C2/c, with Z 4 in a cell of dimensions a 15.593(6), b 7.940(6), c 16.983(6) �, β 107.58(3)�. The structure was refined to a residual R 0.046 for 905 'observed' reflections. Complex (1) is trigonal bipyramidal with the trigonal plane consisting of oxygens from two picolinate ligands [Cu-O 1.995(5) �] and a water molecule [Cu-O 2.080(5) �]. The apical positions are occupied by pyridine ring nitrogens from the Picloram ligands [Cu-N 2.021(5) �]. Bis(4-amino-3,5,6-trichloropyridine- 2-carboxylato)bis(pyrimidin-2-amine)copper(II) (2) is monoclinic, space group P2,/c, with Z 4 in a cell of dimensions a 12.3 11(5), b 15.435(5), c 15.320(6) �, β 115.95(3)�, and gave a final R 0.059 for 2429 'observed' reflections. In complex (2), the copper(II) atom has a tetragonally distorted octahedral stereochemistry with the Picloram ring nitrogens once again occupying the two axial positions [Cu-N 2.586(7) and 2.611(7) �]. The square plane consists of two carboxylato oxygens [Cu-O 1.941(6) and 1.960(7) �] and two hetero-nitrogens from pyrimidin-2-amine ligands [Cu-N 2.048(6) and 2.054(6) �].


2014 ◽  
Vol 70 (12) ◽  
pp. 1101-1104 ◽  
Author(s):  
Eduard B. Coropceanu ◽  
Ana Dreab ◽  
Lilia Croitor

Two new mononuclear coordination compounds, bis{4-[(hydroxyimino)methyl]pyridinium} diaquabis(pyridine-2,5-dicarboxylato-κ2N,O2)zincate(II), (C6H7N2O)2[Zn(C7H3NO4)2(H2O)2], (1), and (pyridine-2,6-dicarboxylato-κ3O2,N,O6)bis[N-(pyridin-4-ylmethylidene-κN)hydroxylamine]zinc(II), [Zn(C7H3NO4)(C6H6N2O)2], (2), have been synthesized and characterized by single-crystal X-ray diffractometry. The centrosymmetric ZnIIcation in (1) is octahedrally coordinated by two chelating pyridine-2,5-dicarboxylate ligands and by two water molecules in a distorted octahedral geometry. In (2), the ZnIIcation is coordinated by a tridentate pyridine-2,6-dicarboxylate dianion and by twoN-(pyridin-4-ylmethylidene)hydroxylamine molecules in a distortedC2-symmetric trigonal bipyramidal coordination geometry.


2016 ◽  
Vol 72 (9) ◽  
pp. 697-700
Author(s):  
Yingying Wang ◽  
Meixia Wen ◽  
Zhongjun Gao ◽  
Ning Sheng

Polynuclear complexes are an important class of inorganic functional materials and are of interest particularly for their applications in molecular magnets. Multidentate chelating ligands play an important role in the design and syntheses of polynuclear metal clusters. A novel linear tetranuclear CoIIcluster, namely bis{μ3-(E)-2-[(2-oxidobenzylidene)amino]phenolato}bis{μ2-(E)-2-[(2-oxidobenzylidene)amino]phenolato}bis(1,10-phenanthroline)tetracobalt(II), [Co4(C14H11NO2)4(C12H8N2)2], was prepared under solvothermal conditions through a mixed-ligand synthetic strategy. The structure was determined by X-ray single-crystal diffraction and bulk purity was confirmed by powder X-ray diffraction. The complex molecule has a centrosymmetric tetranuclear chain-like structure and the four CoIIions are located in two different coordination environments. The CoIIions at the ends of the chain are in a slightly distorted octahedral geometry, while the two inner CoIIions are in five-coordinate distorted trigonal bipyramidal environments. A magnetic study reveals ferromagnetic CoII...CoIIexchange interactions for the complex.


1998 ◽  
Vol 53 (7) ◽  
pp. 699-703 ◽  
Author(s):  
Abdel-Fattah Shihada ◽  
Frank Weller

Abstract Diethylchlorotin dimethylphosphinate has been synthesized by treating (Et2ClSn)2O with HO2PMe2 in toluene. Single crystal X-ray analysis shows that O2PMe2 groups behave as bidentate bridge ligands between Et2ClSn units leading to a polymeric chain structure in which the tin atoms exhibit a distorted trigonal bipyramidal geometry with the oxygen atoms in the axial positions. The Sn-Cl bond lies on a C2 axis of symmetry in the (C2v) OCClSnCO unit. Et2ClSnO2PMe2 crystallizes in the monoclinic space group C2/c (a = 877.9 (2), b = 1907.8 (4), c = 695.5 (1) pm, β= 106.72 (2)°, Z = 4 and R = 0.043). The characteristic IR bands of Et2ClSnO2PMe2 are assigned and the mass spectrum is reported and discussed.


2006 ◽  
Vol 61 (5) ◽  
pp. 555-559 ◽  
Author(s):  
Veysel T. Yilmaz ◽  
Vecdi Kars ◽  
Canan Kazak

The new cadmium and mercury saccharinate (sac) complexes, cis-[Cd(sac)2(dmea)2] (1) and [Hg(sac)2(dmea)(H2O)] (2) (dmea = 2-dimethylaminoethanol), have been prepared and characterized by elemental analysis, IR spectroscopy, thermal analysis and single crystal X-ray diffraction. In complex 1, the cadmium(II) ion is coordinated by two neutral dmea ligands and two sac anions in a distorted octahedral CdN3O3 coordination geometry. The dmea ligand acts as a bidentate N, O chelate, while the sac ligands behave as an ambidentate ligands. One of them coordinates to the cadmium(II) ion through the carbonyl oxygen atom, while the other is N-bonded. In complex 2, the mercury(II) ion is coordinated by an aqua ligand, a chelating dmea ligand and two N-bonded sac ligands, forming a distorted trigonal bipyramidal coordination HgN3O2. The molecules interact with each other through O-H···O hydrogen bonds and aromatic π(sac)···π(sac) stacking interactions, leading to a three-dimensional supramolecular network.


2020 ◽  
Vol 44 (3-4) ◽  
pp. 221-226
Author(s):  
Shakiba Shahmirzaei ◽  
Zahra Mardani ◽  
Keyvan Moeini ◽  
Cameron Carpenter-Warren ◽  
Alexandra MZ Slawin ◽  
...  

A new triazine ligand salt, 2,2′,2″-(1,3,5-triazine-2,4,6-triyl)tris(hydrazin-1-ium) chloride [THT·(HCl)3], and the one-dimensional coordination polymer of cadmium, [Cd2( µ-THT)( µ-Cl)( µ-I)I2]·2(H2O), are prepared and characterized by elemental analysis, Fourier-transform infrared spectroscopy, 1H NMR spectroscopy, and single-crystal X-ray diffraction (for the cadmium polymer). X-ray analysis revealed that the polymeric backbone is extended alternatively by di-iodo and di-chloro bridges; this type of bridge is not observed previously between any metal atoms. There are two types of cadmium atoms in the polymer: cadmium of the polymeric chain and terminal cadmiums. The geometry around the first (CdN2Cl2I2) is octahedral, while the latter (CdN3I2) has an incline to square-pyramidal geometry. The triazine ligand of this structure also bridges two cadmium atoms and acts as an N3 donor toward the terminal cadmium atoms and as an N2 donor toward the cadmium atoms of the chain. In the crystal network of the cadmium polymer, the hydrogen bonds of N–H···X (X: O, N, I) form different hydrogen bond motifs, including [Formula: see text](8), [Formula: see text](10), [Formula: see text](14), [Formula: see text](18), [Formula: see text](20), [Formula: see text](24), [Formula: see text](28), and [Formula: see text](32).


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