Structure and bonding in the neutral and anionic forms of dimethylglyoxime and its complexes

1980 ◽  
Vol 33 (7) ◽  
pp. 1519 ◽  
Author(s):  
CL Raston ◽  
BW Skelton ◽  
AH White

In order to permit a comparative study of the structure and bonding behaviour of dimethylglyoxime in its neutral and monoanionic forms, both 'free' and complexed to transition metals, redeterminations of the crystal structures of dimethylglyoxime, dmgH2, and the complexes Cu(dmgH2)Cl2 and Cu(dmgH2)Br2 have been carried out, together with an initial determination of the structure of the hydrated sodium salt Na2(dmg),8H2O. Crystals of dmgH2 are triclinic, space group Pī, a 6.078(3), b 6.319(3), c 4.492(2) Ǻ, α 122.69(3), β 91.71(4), γ 77.72(4)°, Z 1 the structure was refined to a residual of 0.049 for 748 'observed' reflections. Crystals of Na2(dmg),8H2O are monoclinic, P21/c, a 11.317(7), b 12.995(7), c 4.901(4) Ǻ, β 100.55(5)°, Z 2, the structure being refined to a residual of 0.040 for 942 ?observed? reflections. Crystals of Cu(dmgH2)Cl2 are triclinic, Pī, a 8.163(4), b 8.109(3), c 7.701(2) Ǻ, α 110.88(3), β 101.31(3), γ 108.04(3)°, Z 2; for the isomorphous bromide a 8.628(3), b 8.276(4), c 7.757(2) Ǻ, α 111.18(3), β 101.02(3), γ 108.55(3)°. The two structures were refined to residuals of 0.052 and 0.045 for 964 and 1597 'observed' reflections respectively.

1999 ◽  
Vol 52 (10) ◽  
pp. 983 ◽  
Author(s):  
Yang-Yi Yang ◽  
Seik Weng Ng ◽  
Xiao-Ming Chen

Three tetranuclear copper(II)–lanthanide(III) complexes of triphenylphosphoniopropionate (Ph3P+CH2CH2CO2−,tppp), namely [Cu2Ln2(tppp)8(H2O)8](ClO4)10·2H 2 O [Ln = EuIII, NdIII or CeIII], were synthesized and characterized by crystallography. The EuIII complex crystallizes in the triclinic space group P1 – with a 16.249(7), b 17.185(11), c 17.807(11) Å, α 69.750(10), β 89.230(10), γ 84.070(10)˚, V 4639(5) Å3, Z 1. In the crystal structures, four tppp ligands bridge a pair of CuII and tetraaquo-EuIII atoms (Cu···Eu 3.527(2) Å) through their µ2-carboxylato ends to form a dinuclear subunit; two of these subunits are additionally linked by one of the CuII -bonded carboxylato oxygen ends, across a centre of inversion, to furnish a dimeric tetranuclear [Cu(tppp)4 Eu(H2O)4]2 species (Cu···Cu 3.323(2) Å). This CuII -bonded oxygen atom occupies the apical site of the square-pyramidal coordination environment of the CuII atom. The EuIII atom is eight-coordinated in a square-antiprismatic geometry. The NdIII and CeIII complexes are isomorphous to the EuIII complex, and only minor differences in bond lengths and bond angles involving the metal atoms are noted.


1998 ◽  
Vol 53 (11) ◽  
pp. 1329-1334 ◽  
Author(s):  
L. Homolya ◽  
S. Strueß ◽  
W. Preetz

The crystal structures of cis-(n-Bu4N)2[ReCl4(NCS)2] (triclinic, space group P1̅, a = 11,245( 1), b = 20.174(3), c = 21.320(8) Å, a =109.06(2), β = 96.46(2), γ = 98.22(5)°, Z = 4) and cis-(Ph4P)2[ReCl4(NCSe)2]·2CH2Cl2 (triclinic, space group P1̅, a = 10.341(2), b = 13.436(3), c = 19.616(4) Å, α = 92.70(2), β = 92.02(2), γ = 89.99( 1)°, Z= 2) have been determined by single crystal X-ray diffraction analysis. Both ambidentate ligands NCS and NCSe are bonded via the N atom. Using the molecular parameters of the X-ray determinations the low temperature (10 K) IR and Raman spectra of the (n-Bu4N) salts have been assigned by normal coordinate analysis based on a modified valence force field. The valence force constants fd(ReN) are 1,78(NCS) and 1,79(NCSe) mdyn/ Å.


2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Jing Chen ◽  
You-Juan Zhang ◽  
Kun-Tao Huang ◽  
Qiang Huang ◽  
Jun-Jie Wang

Two new cobalt(II) complexes of formula [Co(hfac)2(NITphtrz) 1 and Co(hfac)2(IMphtrz) 2] have been prepared and characterized structurally [where NITphtrz = 4,4,5,5-tetramethyl-2-(2-phenyl-1,2,3-triazole-4-yl)imidazoline-1-oxyl-3-oxide and IMphtrz = 4,4,5,5-tetramethyl-2-(2-phenyl-1,2,3-triazole-4-yl)imidazoline-1-oxyl]. All of the complexes crystallize in an isomorphous triclinic space group P1- with the Co(II) ion octahedrally coordinated via the bidentate chelating mode. The magnetic measurements show that two complexes exhibit antiferromagnetic interactions between the metal ions and the nitroxide radicals.


2010 ◽  
Vol 66 (6) ◽  
pp. 579-584 ◽  
Author(s):  
Kevin Robertson ◽  
David Bish

X-ray powder diffraction (XRD) data were used to solve the crystal structures of phases in the magnesium perchlorate hydrate system, Mg(ClO4)2·nH2O (n = 4, 2). A heating stage and humidity generator interfaced to an environmental cell enabled in-situ XRD analyses of dehydration reactions under controlled temperatures and partial pressures of H2O (P_{{\rm H}_2{\rm O}}). The crystal structures were determined using an ab initio charge-flipping method and were refined using fundamental-parameter Rietveld methods. Dehydration of magnesium perchlorate hexahydrate to tetrahydrate (348 K) results in a decrease in symmetry (space group = C2), where isolated Mg2+ cations are equatorially coordinated by four H2O molecules with two [ClO4]− tetrahedra at the apices. Further dehydration to the dihydrate (423 K) leads to bridging of the isolated packets to form double corner-sharing chains of octahedra and polyhedra (space group = C2/m).


2005 ◽  
Vol 60 (2) ◽  
pp. 164-168 ◽  
Author(s):  
A. Elmali ◽  
Y. Elerman ◽  
G. Eren ◽  
F. Gümüş ◽  
I. Svoboda

2-(3’-Hydroxypropyl)benzimidazolium (Hhpb) hexa- and tetrachloroplatinate (C10H13N2O)2·[PtCl6] 1 and (C10H13N2O)2·[PtCl4] 2 were synthesized and their crystal structures determined. Compound 1 is monoclinic, space group P21/n, a = 8.800(1), b = 14.389(2), c = 10.264(2) Å, β = 98.540(10)°, V = 1285.3(3) Å3, Z = 2 and Dc = 1.959 g cm−3. Compound 2 is triclinic, space group P1̄, a=7.8480(10), b=9.0460(10), c=9.6980(10) Å ,α =65.420(10), β =68.810(10), γ = 76.770(1)°,V =581.26(4) Å3, Z =1 and Dc =1.969 g cm−3. In both compounds, the Pt atoms reside at a centre of inversion. Compounds 1 and 2 are comprised of 2-(3’-hydroxypropyl)benzimidazolium (Hhpb)+: (C10H12N2O)+ and [PtCl6]2− and [PtCl4]2− ions, respectively, linked by intermolecular hydrogen bonds N...Cl [range from 3.428(3) to 3.584(4) Å ], N···O [2.769(5) Å ] and O···Cl [3.338(4) and 3.321(3) Å ] for 1, and N···Cl [3.162(7) Å ], N···O [2.749(8) Å ] and O···Cl [3.289(6) Å ] for 2.


2012 ◽  
Vol 67 (10) ◽  
pp. 1098-1106 ◽  
Author(s):  
Nicole Pienack ◽  
Diana Schinkel ◽  
Angela Puls ◽  
Marie-Eve Ordolff ◽  
Henning Lühmann ◽  
...  

The two new thiostannate compounds (trenH)2Sn3S7 (1) and {[Mn(tren)]2Sn2S6} (2) (tren=tris-2-aminoethylamine) were obtained under solvothermal conditions. Compound 1 crystallizes in the hexagonal space group P63/mmc with a=13.2642(19), c=19.078(3) Å, V =2906.9(7) Å3. The layered [Sn3S7]2- anion is constructed by Sn3S4 semi-cubes sharing common edges. The layers are characterized by large hexagonal pores with dimensions of about 11×11 Å2. Compound 2 crystallizes in the triclinic space group P1̄ with lattice parameters a=7.6485(7), b=8.1062(7), c=12.1805(11) Å, α =97.367(11), β =103.995(11), γ = 108:762(10)°, V =676.17(10) Å3. The [Sn2S6]4- anion is composed of two edge-sharing SnS4 tetrahedra and joins two Mn2+-centered complexes by Mn-S bond formation. The Mn2+ cation is in a trigonal-bipyramidal environment of four N atoms of the tren ligand and one S atom of the thiostannate anion. Both compounds are semiconductors with a band gap of 2:96 eV for 1 and of 2:75 eV for 2.


1998 ◽  
Vol 53 (2) ◽  
pp. 206-210 ◽  
Author(s):  
D. Sonnak ◽  
W. Preetz

Abstract X-ray structure determinations have been performed on single crystals of trans-(Ph4P)2-[B6H4I2] (1) (triclinic, space group P1̄, a = 9.9680(12), b = 10.9690(11), c = 11.0470(14) Å,α = 88.167(9), β = 80.466(12), γ = 68.839(11)°, Z = 1), mer-(Ph4P)2[B6H3I3] · 2 CH2Cl2 (2)(triclinic, space group P1̄, a = 11.8694(11), b = 15.1699(13), c = 17.051(2) Å, α = 75.118(9), β = 71.953(10), γ = 69.331(8)°, Z = 2), trans-(Ph4P )2[B6H2I4] · 2 CH3CN (3) (monoclinic, space group P21/n, a = 14.9665(10), b = 7.6783(10), c = 23.385(3) Å, β = 95.78(9)°, Z = 2), and (CH2Py2)[B6HI5] (4) (orthorhombic, space group Pnma, a = 13.660(2), b = 11.8711(13), c = 13.839(2) Å, Z = 4). The B6 octahedra are compressed in the direction of the B-I bonds, resulting in shortened diagonal B ··· B distances with average values of the groups I-B ··· B-I = 2.37 and I-B ··· B-H = 2.43 Å as compared with H-B ··· B-H = 2.49 Å.


2009 ◽  
Vol 64 (5) ◽  
pp. 517-524 ◽  
Author(s):  
Michel Fleck ◽  
Ladislav Bohatý

The crystal structures of four alkali salts of maleic acid have been determined by single crystal X-ray diffraction: crystals of rubidium hydrogen maleate, RbH(C4H2O4), are very nearly centrosymmetrical, i. e., only one hydrogen atom position in the crystal structure violates the centrosymmetry. Thus, the space group is Pbc21 rather than Pbcm. The compound is isotypic with potassium hydrogen maleate, KH(C4H2O4), which has previously been described in space group Pbcm. It has been reinvestigated to prove that the correct space group is also Pbc21. The isotypic pair of rubidium hydrogen maleate maleic acid, RbH(C4H2O4) H2(C4H2O4), and caesium hydrogen maleate maleic acid, CsH(C4H2O4)H2(C4H2O4), crystallise in the triclinic space group P1̄. The geometry of the maleate units in these compounds corresponds well to data of other metal maleates. The only significant variation, concerning the intra-anionic hydrogen bond, is discussed. Furthermore, an overview of previously reported metal maleate structures is given, with special regard to the symmetry of the intramolecular hydrogen bond.


1996 ◽  
Vol 51 (10) ◽  
pp. 1443-1448 ◽  
Author(s):  
H. Vogt ◽  
D. Wulff-Molder ◽  
M. Meisel

(p-Bromobenzyl)triphenylphosphonium Bromide, [(p-Br-C6H4-CH2)P(C6H5)3]+Br- · (CH2Cl2)2.5 (1) has been prepared by the reaction of triphenylphosphine with p-bromobenzylbromide and its structure determined (triclinic, space group P1̅, Z = 2, a = 1198.03(12), b = 1245.80(11), c = 1258.42(12)pm, a = 100.170(8), β = 103.543(9), γ = 1 18.158(7)°. The compound exists as Br- anions and [(p-Br-C6H4- CH2)P(C2H5)3]+ cations, with weak interactions between the chlorine atoms of the CH2Cl2 molecules and the bromine bonded in the cation. [p-Br-C6H4-CH2)P(C6H5)3]Br2 (2) and [(p-Br-C6H4-CH2)P(C6H5)3]Br3·(CH2Cl2)1.5 (3) have been obtained by reactions of the corresponding amounts of bromine with 1 in methylenechloride solution. The yellow-red crystals of 2 are orthorhombic, space group Pccn, Z = 8, a = 2060.8(3), b = 1223.6(4), c = 1860.8(3) pm. Compound 2 exists as [p-Br-C6H4-CH2)P(C6HO5)3]+ cations and linear Br2-4 units with a bromide-bromine distance of 297.3(4) pm. The red crystals of (3) are triclinic, space group P1̅, Z = 2, a = 1 171.16(7), b = 1260.97(8), c = 1270.35(7)pm, α = 65.510(5), β = 75.811(5), γ = 62.320(5)°, and contain [(p-Br-C6H4-CH2)P(C6H5)3]+ cations and linear, slightly asymmetrical Br-3 anions. In all cases the cation has a slightly irregular tetrahedral geometry around the P atom.


1996 ◽  
Vol 51 (10) ◽  
pp. 1400-1406 ◽  
Author(s):  
D. Rickert ◽  
W. Preetz

The crystal structures of trans-[PtCl2(acac)2](monoclinic, space group P21/c, a - 7.616(5), b = 12.759(5), c = 7.892(5) Å, β = 118.459(5)°, Z = 2), trans-[PtBr2(acac)2] (triclinic, space group P1̅, a = 7.502(5), b = 7.665(5), c = 8.155(5) Å, α = 114~508(5), β = 94.537(5), γ = 117.669(5)°. Z = 1) and trans-[Pt(SCN)2(acac)2] (triclinic, space group P1̅ , a = 7.9095(10), b = 7.9393( 10), c = 7.9631 Å, a = 114.051 (10), β = 100.955(10), γ = 100.573(10)°, Z = 1) have been determined by single crystal X-ray diffraction analysis. The crystal structure of trans- [Ptl2(acac)2] is known from the literature. To enhance the spectroscopic resolution, the IR and Raman spectra of the four complexes have been measured at low temperature (10 K). Using the X-ray data, normal coordinate analyses based on a modified valence force field have been performed and the normal modes of vibration for the octahedral skeleton [PtX2O4] have been assigned. With a set of 19 or 23 force constants taking into account the inner-ligand vibrations a good agreement between observed and calculated frequencies has been achieved. The valence force constants are e.g.fd (PtCl) = 2.16, fd (PtBr) = 1.45, fd (PtI) = 1.01, fd (PtS) = 1.80 mdyn/Å, and fd (PtO) ranges from 1.89 to 1.91 mdyn/Å.


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