X-ray diffraction, spectral and magnetic studies of the nickel(II) thiocyanate complexes with tridentate 2,6-dithiocarboxamidopyridine SNS and 2,6-dicarboxamidopyridine ONO ligands: Influence of donor atoms on the coordination geometry of nickel

Polyhedron ◽  
2005 ◽  
Vol 24 (10) ◽  
pp. 1221-1231 ◽  
Author(s):  
Ramesh Kapoor ◽  
Ashok Kataria ◽  
Anuradha Pathak ◽  
Paloth Venugopalan ◽  
Geeta Hundal ◽  
...  
2000 ◽  
Vol 53 (6) ◽  
pp. 507 ◽  
Author(s):  
Martin A. Bennett ◽  
Mark Bown ◽  
David C. R. Hockless

From the reaction of [Ru2Cl3(PMe2Ph)6] Cl with the appropriate radical anions, yellow complexes of general formula [Ru(PMe2Ph)3(η4-arene)] [arene = naphthalene (C10H8) (1), anthracene (C14H10) (2), and triphenylene (C18H12) (3)] have been isolated in poor yield and characterized by elemental analysis, n.m.r. (1H, 13C, 31P) spectroscopy and single-crystal X-ray diffraction. Crystal data: (1), monoclinic, C2/c, a 31.096(8), b 12.012(4), c 17.078(8) Å, β 104.41(3)˚, V 6178(4) Å3, ? 8, refined to final R value of 0.032 with use of 3641 reflections [I > 3σ(I)]; (2), monoclinic, C2/c, a 55.909(4), b 14.348(5), c 17.573(5) Å, β 105.41(1)˚, V 13590(6) Å3, Z 16 (two molecules per asymmetric unit), refined to final R value of 0.049 with use of 7770 reflections [I > 3σ(I)]; (3), mono-clinic, Pn, a 9.377(3), b 12.229(3), c 15.975(3) Å, β 103.51(2)˚, V 1781.2 (7) Å3, Z 2, refined to final R value of 0.026 with use of 2830 reflections [I > 3σ(I)]. In each case, coordination of the zerovalent metal fragment Ru(PMe2Ph)3 to the diene section of one of the terminal rings causes the aromatic molecule to be folded by c. 40˚ at the outer carbon atoms of the diene. The coordination geometry about ruthenium is approximately square pyramidal, with the diene and two tertiary phosphines in the equatorial plane and the remaining tertiary phosphine in the axial site.


2005 ◽  
Vol 60 (9) ◽  
pp. 978-983 ◽  
Author(s):  
Sevim Hamamci ◽  
Veysel T. Yilmaz ◽  
William T. A. Harrison

Two new saccharinato-silver(I) (sac) complexes, [Ag(sac)(ampy)] (1), and [Ag2(sac)2(μ-aepy)2] (2), [ampy = 2-(aminomethyl)pyridine, aepy = 2-(2-aminoethyl)pyridine], have been prepared and characterized by elemental analysis, IR spectroscopy, thermal analysis and single crystal X-ray diffraction. Complexes 1 and 2 crystallize in the monoclinic space group P21/c and triclinic space group P1̄, respectively. The silver(I) ions in both complexes 1 and 2 exhibit a distorted T-shaped AgN3 coordination geometry. 1 consists of individual molecules connected into chains by N-H···O hydrogen bonds. There are two crystallographically distinct dimers in the unit cell of 2 and in each dimer, the aepy ligands act as a bridge between two silver(I) centers, resulting in short argentophilic contacts [Ag1···Ag1 = 3.0199(4) Å and Ag2···Ag2 = 2.9894(4) Å ]. Symmetry equivalent dimers of 2 are connected by N-H···O hydrogen bonds into chains, which are further linked by aromatic π(py)···π(py) stacking interactions into sheets.


1990 ◽  
Vol 45 (11) ◽  
pp. 1508-1512 ◽  
Author(s):  
Michel Mégnamisi-Bélombé ◽  
Bernhard Nuber

The ammonium salts of the complex anions trans-diiodobis(ethanedial-dioximato)-cobaltate(III), [Col2(GH)2]-, and trans-diiodobis(ethanedial-dioximato)rhodate(III), [RhI2(GH)2]- (GH- = ethanedial dioximate or glyoximate), have been synthesized and their structures determined from single crystal X-ray diffraction data at room temperature. The crystals of the two salts are monoclinic, space group C2/c. NH4[CoI2(GH)2] (I) crystallizes as dark-brown prisms with a greenish reflectance; its crystal data are: C4H10Col2N5O4, Mr = 504.90; a = 8.910(6), b = 11.700(9), c = 11.691(6) Å; β = 93.55(5)°; V = 1216.4 Å3; Z = 4; Dc = 2.78 Mg m-3. NH4[RhI2(GH)2] (II) crystallizes as yellow-brown blocks with crystal data: C4H10I2N5O4Rh, Mr = 548.88; a = 9.038(4), b = 11.949(5), c = 11.770(3) Å; β = 95.54(3)°; V = 1265.16 A3; Z = 4; Dc = 2.87 Mg m-3. The two structures were refined to a final RW = 0.045 for 1209 observed independent reflections and 95 parameters for I, and to a final RW = 0.040 for 1922 observed independent reflections and 87 parameters for II. The coordination geometry around Co or Rh in the anionic complexes is a distorted (4 + 2) octahedron of four equatorial chelating N atoms and two apical iodides. The H atoms of the hydroxyl groups are involved, as usual, in intramolecular O—H—O bridges with uniform Ο···Ο separations of 2.582 Å for I, and 2.713 Å for II. The rectilinear I—Co—I or I—Rh—I triads form “infinite” zigzag chains extending parallel to the ab plane, with a weak I—I contact of 3.988 Å for I, and 4.010 Å for II.


1993 ◽  
Vol 48 (6) ◽  
pp. 771-777 ◽  
Author(s):  
Ulrich Abram ◽  
Bernd Lorenz

Novel rhenium complexes with terminal thiocarbonyl groups have been synthesized from ReCl3(Me2PhP)3 and sodium diethyldithiocarbamate. mer-(Diethyldithiocarbamato)tris-(dimethylphenylphosphine)(thiocarbonyl)rhenium(I), mer-[Re(CS)(Me2PhP)3(Et2dtc)], and tris(diethyldithiocarbamato)(thiocarbonyl)rhenium(III), [Re(CS)(Et2dtc)3] have been studied by infrared and NMR spectroscopy, mass spectrometry and X-ray diffraction.mer-[Re(CS)(Me2PhP)3(Et2dtc)] crystallizes orthorhombic in the space group Pna21 with a = 1516.1(2), b = 2189.8(2) and c = 1035.6(1) pm. Structure solution and refinement converged at R = 0.042. The coordination geometry is a distorted octahedron. The Re—C bond length is found to be 184(2) pm.[Re(CS)(Et2dtc)3] crystallizes monoclinic in the space group P21/c with a = 962.2(6), b = 1744.0(2), c = 1537.4(6) pm and β = 96.21(1)°. The final R value is 0.028. In the monomeric complex the rhenium atom is seven-coordinate with an approximate pentagonal-bipyramidal coordination sphere and a rhenium-carbon distance of 181(1) pm.


1980 ◽  
Vol 43 (329) ◽  
pp. 659-663 ◽  
Author(s):  
M. J. Wort ◽  
M. P. Jones

SynopsisIT was not until 1966 that pseudorutile was first defined. Earlier, its X-ray diffraction spectrum had been confused with that of futile and, to a lesser degree, with those of hematite and ilmenite. Subsequent work has shown that pseudorutile has a world-wide distribution in detrital ilmenite-bearing heavy mineral deposits. The present work has confirmed its magnetic susceptibility and density. In addition pseudorutile is shown to be a magnetic spin glass with a peak susceptibility at 23 °K.Altered ilmenites, in which pseudorutile occurs as a secondary alteration product, display a range of chemical composition and magnetic susceptibility. The most highly magnetic fractions are not necessarily those containing the least-altered ilmenite, and in material from Capel, Western Australia, the most highly magnetic fractions were those containing grains of ferrimagnetic ferrian ilmenite.Quantitative X-ray diffraction has shown that West Australian altered ilmenite contains significant amounts of amorphous ilmenite, pseudorutile, and rutile. The magnetic susceptibility of paramagnetic fractions of altered ilmenite from Capel, Western Australia, can be calculated from normative compositions based on chemical analyses.


1980 ◽  
Vol 33 (11) ◽  
pp. 2369 ◽  
Author(s):  
E Horn ◽  
MR Snow

The complexes Re(CO)5ClO4, Re(CO)5PO2F2, L2(CO)3Re(OClO3) and L2(CO)3Re(PO2F2), where L2 = 2,2?-bipyridyl (bpy), have been synthesized by bromide abstraction reactions from the respective rhenium carbonyl bromide precursors. The complexes were characterized by infrared and mass spectroscopy. The crystal structure of (bpy)(CO)3Re(PO2F2) has been determined from X-ray diffraction data by the heavy-atom technique. The crystals are triclinic, space group Pī with a 8.620(3), b 15.912(5), c 6.466(3) Ǻ, α 102.08(8), β 83.29(8), γ 95.08(4) and Z 2. The structure has been refined by full-matrix least-squares from 2829 reflections to R = 0.084, Rw = 0.088. The coordination geometry about rhenium is that of a distorted octahedron. Difluorophosphate coordinates to the metal centre by one of its oxygen atoms. Formation of the difluorophosphate by hydrolysis of hexafluorophosphate was shown by 31P n.m.r. spectra.


1990 ◽  
Vol 45 (10) ◽  
pp. 1369-1382 ◽  
Author(s):  
Heindirk tom Dieck ◽  
Lutz Stamp

Diazadienes RN = CR′-CR′ = NR (DAD) form molecular complexes with copper(I) halides of composition (DAD)CuX, the structures of which vary from [(DAD)2Cu]+(CuCl2)⁻ with a non-tetrahedral bis(chelated) cation, over [(DAD)CuCl]2 with asymmetrically bridging chloro ligands to planar three-coordinate (DAD)CuCl. The composition of the isolated complexes depends on the relative concentrations or on the solvent. The “soft” coordination geometry of copper is underlined by the structure of the coordination polymer of composition (DAD)2Cu5Cl5, in which Cu atoms of coordination number 2, 3 and 4 and very irregular geometries are encountered and where the DAD ligands are exclusively bridging. Halide ions and sp2-nitrogen donors are very competitive. Bridging DAD ligands are also encountered in (DAD)Cu-Y with the less nucleophilic anions trifluoromethane-sulphonate or perchlorate. Crystal and molecular structures are established for all these coordination geometries and the causes are discussed for the coordination flexibility of copper(I)


2007 ◽  
Vol 62 (1) ◽  
pp. 55-65 ◽  
Author(s):  
Joseph Grobe ◽  
Kai Lütke-Brochtrup ◽  
Bernt Krebs ◽  
Mechtild Läge ◽  
Hans-Hermann Niemeyer ◽  
...  

The tripod phosphane ligand FSi(CH2CH2PMe2)3 (1) has been prepared again and attempts to generate F3CSi(CH2CH2PMe2)3 (2) were undertaken for the preparation of transition metal cage compounds of the type A(CCP)3M or A(CCP)3M-L (A = FSi, F3CSi). The photochemical addition of dimethylphosphane to trifluoromethyl-trivinylsilane, however, gave 1 instead of the expected CF3Sitripod ligand 2, obviously due to difluorocarbene elimination. 1 was used to prepare the chromium carbonyl derivative (CO)3Cr[(Me2PCH2CH2)3SiF] (3) from Cr(CO)3CHT, and 3 was characterized by NMR and IR spectroscopy. The novel complex FSi(CH2CH2PMe2)3Pd (4) and its PPh3 derivative [FSi(CH2CH2PMe2)3Pd]PPh3 (5) have been obtained by reacting 1 with Pd(PPh3)4 and were characterized by NMR (4) and X-ray diffraction (5). The data prove the expected Pd→Si interaction by characteristic coordination shifts and a Pd-Si distance of 3.875 Å which is smaller than the Ni-Si distance in the corresponding nickel compound (3.92 Å ). The preparation of the analogous platinum complex from the precursors Pt(PPh3)4, Pt(C7H10)3, or (Ph3P)2Pt(η2-C2H4) failed, whereas the reaction of 1 with Pt(PEt3)4 was successful, but surprisingly led to the trinuclear complex [FSi(CH2CH2PMe2)3Pt]3(PMe2CH2CH2)3SiF (6) with three cages of type 4 and an additional ligand 1 as a bridging unit. Complex 6 was isolated and characterized spectroscopically. Quantum chemical calculations have been used to elucidate the coordination geometry expected for 4, 5 and the corresponding platinum cage 4′ in 6. The calculations support the structure of 5 within the expected limitations of the experimental and theoretical methods and - in spite of the extremely soft coordination sphere of the studied cages - are in accord with the spectroscopic results.


2019 ◽  
Vol 75 (8) ◽  
pp. 1073-1083 ◽  
Author(s):  
Feng Su ◽  
Cheng-Yong Zhou ◽  
Lin-Tao Wu ◽  
Xi Wu ◽  
Jing Su ◽  
...  

Two CoII-based coordination polymers, namely poly[(μ4-biphenyl-2,2′,5,5′-tetracarboxylato){μ2-1,3-bis[(1H-imidazol-1-yl)methyl]benzene}dicobalt(II)], [Co2(C16H6O8)(C14H14N4)2] n or [Co2(o,m-bpta)(1,3-bimb)2] n (I), and poly[[aqua(μ4-biphenyl-2,2′,5,5′-tetracarboxylato){1,4-bis[(1H-imidazol-1-yl)methyl]benzene}dicobalt(II)] dihydrate], {[Co2(C16H6O8)(C14H14N4)2(H2O)2]·4H2O} n or {[Co2(o,m-bpta)(1,4-bimb)2(H2O)2]·4H2O} n (II), were synthesized from a mixture of biphenyl-2,2′,5,5′-tetracarboxylic acid, i.e. [H4(o,m-bpta)], CoCl2·6H2O and N-donor ligands under solvothermal conditions. The complexes were characterized by IR spectroscopy, elemental analysis, single-crystal X-ray diffraction and powder X-ray diffraction analysis. The bridging (o,m-bpta)4− ligands combine with CoII ions in different μ4-coordination modes, leading to the formation of one-dimensional chains. The central CoII atoms display tetrahedral [CoN2O2] and octahedral [CoN2O4] geometries in I and II, respectively. The bis[(1H-imidazol-1-yl)methyl]benzene (bimb) ligands adopt trans or cis conformations to connect CoII ions, thus forming two three-dimensional (3D) networks. Complex I shows a (2,4)-connected 3D network with left- and right-handed helical chains constructed by (o,m-bpta)4− ligands. Complex II is a (4,4)-connected 3D novel network with ribbon-like chains formed by (o,m-bpta)4− linkers. Magnetic studies indicate an orbital contribution to the magnetic moment of I and II due to the longer Co...Co distances. An attempt has been made to fit the χM T results to the magnetic formulae for mononuclear CoII complexes, the fitting indicating the presence of weak antiferromagnetic interactions between the CoII ions.


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