Steric effects in a distorted square planar bis-(2,2′-bipyridyl) metal complex: X-ray crystal structure of aquobis-(2,2′-bipyridyl)palladium(II) nitrate

Author(s):  
A. J. Carty ◽  
P. C. Chieh
2007 ◽  
Vol 62 (9) ◽  
pp. 1133-1138 ◽  
Author(s):  
Veli T. Kasumov ◽  
Ibrahim Uçar ◽  
Ahmet Bulut ◽  
Fevzi Kösal

The coordination chemistry of N-(2,6-di-methylphenyl)-2-hydroxy-3-methoxybenzaldimine (1) with Cu(II) has been investigated by X-ray crystallography, electronic and EPR spectroscopies, as well as by electro- and magnetochemistry. The title complex 2 crystallizes in the orthorhombic space group P212121 (a = 8.1538, b = 17.7466, c =19.8507 Å). The mononuclear square-planar molecules 2 featuring trans-N2O2 coordination are connected via weak intermolecular C-H· · ·π interactions into infinite chains parallel to the a axis. Although the intermolecular Cu· · ·Cu separations within individual chains and between chains are very long (8.154 and 9.726 Å ), the exchange interaction parameter G = 2.03 < 4, estimated from solid state EPR spectra, suggests the existence of long-distance superexchange pathways between adjacent Cu(II) centers. The electronic and electrochemical features of the compound are also discussed.


1979 ◽  
Vol 57 (1) ◽  
pp. 57-61 ◽  
Author(s):  
R. Melanson ◽  
F. D. Rochon

The crystal structure of [Pt(diethylenetriamine)(guanosine)](ClO4)2 has been determined by X-ray diffraction. The crystals are orthorhombic, space group P212121, with a = 12.486(6), b = 13.444(7), c = 14.678(11) Å, and Z = 4. The structure was refined by block-diagonal least-squares analysis to a conventional R factor of 0.050 and a weighted Rw = 0.045.The coordination around the platinum atom is square planar. Guanosine is bonded to platinum through N(7). The purine planar ring makes an angle of 62.7° with the platinum coordination plane. The structure is stabilized by hydrogen bonding.


IUCrData ◽  
2019 ◽  
Vol 4 (11) ◽  
Author(s):  
Artem V. Malin ◽  
Sergei I. Ivlev ◽  
Roman V. Ostvald ◽  
Florian Kraus

Single crystals of rubidium tetrafluoridobromate(III), RbBrF4, were grown by melting and recrystallizing RbBrF4 from its melt. This is the first determination of the crystal structure of RbBrF4 using single-crystal X-ray diffraction data. We confirmed that the structure contains square-planar [BrF4]− anions and rubidium cations that are coordinated by F atoms in a square-antiprismatic manner. The compound crystallizes in the KBrF4 structure type. Atomic coordinates and bond lengths and angles were determined with higher precision than in a previous report based on powder X-ray diffraction data [Ivlev et al. (2015). Z. Anorg. Allg. Chem. 641, 2593–2598].


1995 ◽  
Vol 2 (2) ◽  
pp. 81-90 ◽  
Author(s):  
Angel Garcia-Raso ◽  
Juan J. Fiol ◽  
Elies Molins ◽  
Antonia M. Calafat ◽  
Patricia A. Marzilli ◽  
...  

The first X-ray structure of an isatin (2,3-indolinedione, isaH) metal complex, bis(isatinato)memury(II) (C16H8N2O4Hg) (1), was determined. (1) was obtained from the reaction of isaH with mercury(II) acetate in methanol. Analogously, treatment of sodium saccharinate and mercury(II) acetate in methanol yielded Hg(saccharinato)2•0.5CH3OH (3). (1) crystallizes in the monoclinic system, space group P21/a with a = 7.299(1) Å, b = 8.192(1) Å, c = 11.601(1) Å , β = 105.82(1)°, V = 667.4 Å3, Z = 2, Dcalc = 2.452 g cm−3, MoKα radiation(λ = 0.71073 Å), μ = 115.5 cm-1, F(000) = 460, 21(1) °C. The structure was refined on the basis of 2023 observed reflections to R= 0.044. The two deprotonated, non coplanar isa ligands are trans to each other in a head to tail orientation and bound to the Hg through the nitrogen in a linear N-Hg-N arrangement. The Hg atom is at the center of symmetry of the complex and displaced by 0.62 Å from the two planes of the isa ligands (τ Hg-N1-C2-O2= -16°). The Hg-N bond length is 2.015 Å. Noπ-aryl-memury(ll)-π-aryl stacking interaction was observed either in the solid state or in the solution state. The IR, electronic, and H1 and C13NMR spectral data of (1) and (3) suggest binding of the memury to the heterocyclic nitrogen, in agreement with the crystal structure determination of (1).


2020 ◽  
Vol 76 (11) ◽  
pp. 1005-1009
Author(s):  
Mehdi Khalaj ◽  
Abolfazl Olyaei ◽  
Mahdieh Sadeghpour ◽  
Arash Lalegani ◽  
Janusz Lipkowski ◽  
...  

A novel complex has been prepared using the (E)-4-nitro-N-(pyridin-2-ylmethylidene)aniline bidentate Schiff base ligand and PtCl2, namely, dichlorido[(E)-4-nitro-N-(pyridin-2-ylmethylidene)aniline-κ2 N,N′]platinum(II) acetonitrile hemisolvate, [PtCl2(C12H9N3O2)]·0.5CH3CN, 1. According to the X-ray measurements of the crystal structure, the PtII ion adopts a PtCl2N2 square-planar coordination. The coordination of the Schiff base ligand to the PtII ion occurs in a cyclic bidentate fashion, as a result of which a five-membered metallacycle is formed. Furthermore, in the structure of 1, the neutral molecules form a one-dimensional chain structure through C—H...Cl and C—H...O hydrogen bonds. The characterization of the complex was performed via single-crystal X-ray diffraction, IR spectroscopy and elemental analysis, and the antioxidant activity of the complex was evaluated using spectrophotometry by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method.


2008 ◽  
Vol 72 (3) ◽  
pp. 771-783 ◽  
Author(s):  
L. Bindi ◽  
M. D. Welch ◽  
P. Bonazzi ◽  
G. Pratesi ◽  
S. Menchetti

AbstractThe crystal structure of seeligerite, Pb3IO4Cl3, from the San Rafael mine, Sierra Gorda, Chile, was solved in the space group Cmm2, and refined to R = 3.07%. The unit-cell parameters are: a = 7.971(2), b = 7.976(2), c = 27.341(5) Å, V = 1738.3(6) Å3 and Z = 8. The crystal structure consists of a stacking sequence along [001] of square-net layers of O atoms and square-net layers of Cl atoms with Pb+ and I+ cations located in the voids of the packing. As is typical of cations with a stereoactive lone-pair of electrons, Pb2+ and I5+ adopt strongly-asymmetrical configurations. Pb2+ cations occur in a variety of coordination polyhedra, ranging from anticubes and monocapped anticubes to pyramidal ‘one-sided’ coordinations. I5+ is coordinated by a square of four oxygen atoms: I1 and I3 exhibit a ‘one-sided’ coordination, whereas I2 has square-planar coordination.The TEM investigation has revealed additional superlattice reflections (which were not registered by X-ray diffraction (XRD)) in the hk0 diffraction pattern of seeligerite based upon a 0.158 Å-1 square net, which can be interpreted as arising from a 20-cation super-sheet motif (12.6 Å x 12.6 Å), likely related to a further level of Pb-I order superimposed upon the 8-site motif identified by XRD.


1989 ◽  
Vol 44 (9) ◽  
pp. 999-1002 ◽  
Author(s):  
Wolfgang Hiller ◽  
Joachim Strähle ◽  
Alfred Zinn ◽  
Kurt Dehnicke

Ph—C(NSiMe3)2AuCl2 has been prepared by the reaction of N,N,N′-tris(trimethylsilyl)-benzamidine with AuCl3 in CH2Cl2 suspension, forming orange-red crystals, which were characterized by an X-ray structure determination.Space group P21/n, Z = 4, 2358 observed independent reflexions, R = 0.028. Lattice dimensions (20°C): a = 695.9(3); b = 1576.1(3); c = 1830.9(3) pm; β = 94.27(3)°. The compound forms monomeric molecules, in which the gold atom is in a square planar arrangement of the two nitrogen atoms of the benzamidinato chelate (Au—N 201.6(7); 203.3(6) pm) and by two chlorine atoms (Au—Cl 227.9(3); 228.5(2) pm).


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