Thiosemicarbazide complexes of mercury (II) halides

1978 ◽  
Vol 56 (19) ◽  
pp. 2526-2529 ◽  
Author(s):  
Chung Chieh ◽  
Laura P. C. Lee ◽  
Cecilia Chiu

Dibromobis(thiosemicarbazide)mercury(II), HgBr2(tsc)2, is isostructural with dichlorobis-(thiosemicarbazide)mercury(II). The crystal is orthorhombic with a = 8.825(9), b = 8.587(11), c = 15.939(22) Å, Z = 4, space group Pbcn. Some bond lengths and angles are: Hg—Br = 2.860(4) Å, Hg—S = 2.45(1) Å, C—S = 1.76(4) Å and [Formula: see text]. In both HgCl2(tsc)2 and HgBr2(tsc)2, the configuration of the coordinated thiosemicarbazide (tsc) is the same as that of the free molecule. The ir and Raman (R) spectra for the complexes and tsc in the region 300–1600 cm−1 are very similar. The strong band at 800 (807 R) cm−1 in the tsc due to v(C—S) is shifted to 773 (796 R), 777 (796 R), and 660 (680 R) cm−1 for HgCl2−(tsc)2, HgBr2(tsc)2, and HgCl2(tsc) correspondingly. A strong band at 368 (R) cm−1 present uniquely for HgCl2(tsc) can be assigned to v(Hg—N), The halides in HgX2(tsc)2 are bonded to one mercury(II) ion and weakly bridged to a neighboring molecule with Hg … Cl = 3.250(3) Å and Hg…Br = 3.436(4) Å. As a result, two Raman bands due to Hg—X are expected. For HgCl2(tsc)2, the two Raman bands occur at 236 and 166 cm−1, whereas for HgBr2(tsc)2, one was observed at 190 cm−1 but the other was masked by lattice modes. In HgCl2(tsc), the two Hg—Cl bonds are different and bands at 220 and 190 cm−1 are assigned to v(Hg—Cl)t.

1985 ◽  
Vol 40 (3) ◽  
pp. 443-446 ◽  
Author(s):  
Udo Demant ◽  
Elke Conradi ◽  
Ulrich Müller ◽  
Kurt Dehnicke

[HC(NH2)2]3FeCl6 was obtained together with other products from the reaction of S4N4 with HCl in H2CCl2 in the presence of FeCl3. Its crystal structure was determined from X-ray diffraction data (473 independent observed reflexions, R = 0.047). Lattice constants: a = 961.6, c = 876.4 pm; tetragonal, space group P42/m, Z = 2. Of the two crystallographically independent formamidinium ions HC(NH2)2⊕, one exhibits positional disorder; the other one has C-N bond lengths of 128 pm. The FeCl63⊖ ions have symmetry C2h, but the deviation from Oh is small.


1963 ◽  
Vol 41 (12) ◽  
pp. 2983-2987 ◽  
Author(s):  
W. R. Cullen ◽  
J. Trotter

Crystals of bis(diphenylarsenic) oxide are monoclinic, with four molecules in a unit cell of dimensions a = 11.48, b = 30.2, c = 5.97 Å, β = 93.8°, space group P21/n. The structure has been determined from projections along the a and c axes, using Fourier and difference syntheses. The As—O—As angle is 137°, the increase from the normal oxygen valency angle probably being a result of pπ—dπ bonding involving arsenic 4d orbitals. The As—O distance is 1.67 Å, and all the other bond lengths and angles are normal. The orientations of the substituent phenyl groups have been determined.


1962 ◽  
Vol 40 (6) ◽  
pp. 1113-1117 ◽  
Author(s):  
W. R. Cullen ◽  
J. Trotter

Crystals of o-phenylenediarsine oxychloride, C6H4As2Cl2O, are monoclinic with four molecules in a unit cell of dimensions a = 14.50, b = 8.38, c = 7.66 Å, β = 105.8°, space group C2/c. The structure has been determined from projections along the b and c axes. Each molecule is situated on a 2-fold symmetry axis and is planar except for the chlorine atoms, which lie one on either side of the plane of the other atoms. The values of the bond lengths and valency angles have been obtained. Abnormal valency angles at the arsenic and oxygen atoms are the result of their presence in the five-membered ring, and the unusual stability of the molecule in spite of these angles can be interpreted in terms of aromatic character, involving dπ–pπ bonding. The intermolecular separations correspond to normal van der Waals interactions.


1978 ◽  
Vol 33 (8) ◽  
pp. 881-883 ◽  
Author(s):  
Wolfgang May ◽  
Hans Georg von Schnering

Abstract By the weak acid interaction of polymeric phosphanes the condensation of ethylendi-amine yields in a small amount bicyclo-[4,4,0]-1,4,6,9-tetraazadecane C6H14N4. The compound crystallizes triclinic in the space group P1̅ with a = 841.6 pm, b - 463.6 pm, c = 529.2 pm, a= 109.05°, β= 108.35°, γ = 84.13° and Z= 1 formula unit per unit cell. The two condensed six-membered rings have chair conformations. The mean N-C bond lengths are 146.0 pm, the bridging C-C bond is 150.3 pm, whereas the other C-C bonds are 155.1 pm. Structure and condensation reaction are discussed.


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.


1988 ◽  
Vol 41 (3) ◽  
pp. 283 ◽  
Author(s):  
GB Robertson ◽  
PA Tucker

The structures of two crystalline modifications of mer -(Pme2Ph)3H-cis-Cl2IrIII, (1), have been determined from single-crystal X-ray diffraction data. Modification (A) is monoclinic, space group P21/c with a 12.635(1), b 30.605(3), c 14.992(2)Ǻ, β 110.01(2)° and Z = 8. Modification (B) is orthorhombic, space group Pbca with a 27.646(3), b 11.366(1), c 17.252(2)Ǻ and Z = 8. The structures were solved by conventional heavy atom techniques and refined by full-matrix least- squares analyses to conventional R values of 0.037 [(A), 8845 independent reflections] and 0.028 [(B), 5291 independent reflections]. Important bond lengths [Ǻ] are Ir -P(trans to Cl ) 2.249(1) av. (A) and 2.234(1) (B), Ir -P(trans to PMe2Ph) 2.339(2) av. (A) and 2.344(1), 2.352(1) (B), Ir-Cl (trans to H) 2.492(2), 2.518(2) (A) and 2.503(1) (B) and Ir-Cl (trans to PMe2Ph)2.452(2) av. (A) and 2.449(1)(B). Differences in chemically equivalent metal- ligand bond lengths emphasize the importance of non-bonded contacts in determining those lengths.


2007 ◽  
Vol 71 (06) ◽  
pp. 641-650 ◽  
Author(s):  
L. Bindi ◽  
M. Evain ◽  
P. G. Spry ◽  
K. T. Tait ◽  
S. Menchetti

Abstract The pearceite-polybasite group of minerals, general formula [M6T2S7][Ag9CuS4] with M = Ag, Cu; and T = As, Sb, show a crystal structure which can be described as the succession, along the c axis, of two pseudo-layer modules: a [M6T2S7]2– A module layer and a [Ag9CuS4]2+ B module layer. Copper is present in one structural position of the B module layer and replaces Ag in the only fully occupied M position of the A module layer. When the Cu content is >4.00 a.p.f.u., the structural position of the A module layer becomes Cu-dominant and, consequently, the mineral deserves its own name. In this paper we report the crystal-chemical characterization of two Cu-rich members exhibiting the 111 unitcell type (corresponding to the Tac polytype). One sample (space group (P )m1, a 7.3218(8), c 11.8877(13) Å, V 551.90(10) Å3, Z = 1) having As >Sb and with the structural position of the A module layer dominated by Cu, has been named cupropearceite and the other sample (space group (P3̄)m1, a 7.3277(3), c 11.7752(6) Å, V 547.56(8) Å3, Z = 1) having Sb >As has been named cupropolybasite. Both the new minerals and mineral names have been approved by the IMA-CNMNC.


1984 ◽  
Vol 62 (7) ◽  
pp. 1363-1368 ◽  
Author(s):  
Wolfgang Kliegel ◽  
Steven J. Rettig ◽  
James Trotter

Crystals of (salicylaldoximato-O,N)diphenylboron are triclinic, a = 10.125(2), b = 10.797(1), c = 14.760(2) Å, α = 89.05(1), β = 86.98(1), γ = 83.18(1)°, Z = 4, space group [Formula: see text]. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to R = 0.040 and Rw = 0.048 for4145 reflections with I ≥ 3σ(I). The structure consists of two crystallographically independent, but essentially identical, molecules linked by strong [Formula: see text] hydrogen bonds to form continuous spirals along the a axis. The Ph2B moiety is chelated by the phenolic oxygen and oxime nitrogen atoms of the ligand resulting in the formation of a non-planar six-membered chelate ring. Important libration-corrected mean bond lengths are O—B = 1.516(1), N—B = 1.609(2), and C—B = 1.613(2) Å.


1982 ◽  
Vol 37 (2) ◽  
pp. 195-197 ◽  
Author(s):  
Dietmar Schomburg

Abstract Hexamethylendiammonium-bis(ethylenedioxy)methylsilane crystallizes in the hexagonal space group P6122, Z = 6 with a= 11.902(1), c = 30.148(4) A. The structure was refined to R - 0.041 using 2281 independent reflections. The geometry around the pentacoordinate silicon atom is between a trigonal bipyramid and a square pyramid. Oeq-Si-Oeq 136.0(1)°, Oax-Si-Oax 161.7(1)°. The Si-Oax bond lengths are 1.749(2) and 1.769(2) A, the Si-Oeq 1.711(2) and 1.735(2) A, Si-Ceq 1.876(3) A. The compound forms strong N-H ··· O hydrogen bonds between cation and anion. The cation lies on a crystallographic twofold axis


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.


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