Branka Korpar-Čolig

The crystal and molecular structure of tetrakis(cyanomercuri)methane hydrate

The crystal structure of tetrakis(cyanomercuri)methane hydrate, C(HgCN)4 · H2O, has been determined from diffractometer X-ray intensity data by means of Patterson and Fourier methods and refined by the least-squares technique based on 911 independent reflections to the index R of 0.058 and Rω of 0.065. Crystals are monoclinic holohedral, space group P21/n with Z 4 formula units in the unit cell of dimensions a 8.520(5), b 13.622(8), c 10.783(6) A, β 92.48(5)°, Dobs 4.99 g cm−3, Dcalc 4.97 g cm−3. The structure consists of discrete molecules of tetrakis(cyanomercuri)methane and molecules of water of crystallization. The bond angles at the methane carbon atom range from 105(2) to 114(3)° and the mean HgC(methane) bond length is 2.05(3) A, while the distance of all the four mercury atoms from the geometrical centre of the tetrahedron is 2.053(3) A. The CHgC bond angles range from 175(3) to 178(2)°. The mean value of the HgC(cyanide) bond length is 2.03 A. The one OH⋯N hydrogen bond per water molecule is 2.77 A long.

Infrared, Raman and force field studies of tetrakis(anionomercuri)methanes

Abstract In order to throw light on the nature of the HgC bond in permecurated methanes, the infrared and Raman spectra of solid tetrakis(anionomercuri)methanes, C(HgX) 4 (X = CN − , HCOO − , CH 3 COO − and CF 3 COO − ) have been assigned in the range 4000−40 cm −1 . For these four as well as for other molecules of this type (X = F − , Cl − , Br − , I − and SCH 3 − ) the force fields for the CHg 4 tetrahedron have been calculated. The HgC force constants are 18 to 28% lower than in the related Hg(CH 3 )X compounds; since the HgC bond lengths are approximately the same in both linear and tetrahedral configuration, this can be explained in terms of the nonbonded interactions between mercury atoms.

Mercuration Products of Some Aliphatic Ketones and Keto-Acids. 1H and 13C NMR Evidence on the Site and Degree of Mercuration. The Crystal and Molecular Structure of 1-(Acetoxymercurio) Butanone

Trimercurated acetone, CH3COC(HgX)3, X = CH3OCO−, NO3 −, is formed by direct mercuration of acetone. The reaction of propyne with aqueous mercuric chloride leads to a mixture of trimercurated acetone, CH3COC (HgCl)3, dimercurated acetone, CH3COCH(HgCl)2 and trace amounts of monomercurated acetone, CH3COCH2HgCl. Direct mercuration of butanone with mercuric acetate leads to the mixture of trimercurated butanone, C2H5COC(HgOCOCH3)3, dimercurated butanone, C2H5COCH(HgOCOCH3)2, and monomercurated butanone, C2H5COCH2HgOCOCH3. 1-(Acetoxymercurio)butanone, C2H5COC(HgOCOCH3)3, was characterized by X-ray diffraction. It crystallizes in the orthorhombic system, space group Pbca, a = 25.147(6), b = 11.861(3), c = 5.267(1) A, Z = 8, D c = 2.797 gcm−3, 888 unique reflections with I > 3σ(I), R = 0.065. The reaction of butyne with aqueous mercuric chloride leads to only tri- and dimercurated butanones. The one- and two-dimensional 1H and 13C NMR spectra of soluble chloromercurio derivatives of acetone and butanone reveal...

Synthesis and characterization of octamolybdates containing co-ordinatively bound salicylideneiminato and methioninato (MetO) ligands. Crystal structures of [NH3Pr]2[Mo8O22(OH)4(OC6H4CHNPr-2)2]·6MeOH and [Hmorph]4[Mo8O24(OH)2(MetO)2]·4H2O (morph = morpholine)

The compound [MoO2(sal)2](Hsal = salicylaldehyde) reacts with n-propylamine in methanol to give [NH3Pr]2[Mo8O22(OH)4(OC6H4CHNPr-2)2]·6MeOH (1). The same complex was obtained by the reaction of ammonium paramolybdate with N-propylsalicylideneimine. The structure determined by X-ray analysis showed that the octamolybdate anion consists of eight condensed octahedra with 16 terminal positions, two of which are occupied by the salicylideneiminato ligands. The reaction of MoO2Cl2 with methionine yields the neutral complex [Mo8O20(OH)4(MetO)4]·solvent (2)(solvent = H2O or MeOH, MetO = methioninate). If the methanolic solution of (2) is neutralized with morpholine (morph) the anionic complex [Hmorph]4[Mo8O24(OH)2(MetO)2]·4H2O (3) is obtained. It has been shown by X-ray analysis that the structure of (3) is analogous to that of (1) with two MetO ligands linked to two terminal sites of the Mo8O26 core.

Mercuretin as the condensation polymer of tris(acetoxymercuri)acetic acid. The crystal structure of (ClHg)3CCOOH · DMSO

Abstract It has been confirmed that the compound obtained by melting mercuric acetate (Stromeyer, 1809; Dimroth, 1902), named mercuretin (Marsh and Fleming Struthers, 1927), is identical with the compound prepared by heating mercuric acetate in acetic anhydride (Sand and Singer, 1903). Mercuretin, prepared by both routes, has been identified as the condensation polymer of tris(acetoxymercuri)acetic acid, AcO[HgC(HgOAc)2COO]nH, with n ∼ 10. Its hydrolysis in dilute hydrochloric acid gives tris(chloromercuri)acetic acid as the only mercury-containing product. The crystal structure of tris(chloromercuri)acetic acid dimethylsulfoxide solvate, (ClHg)3CCOOH · DMSO, has been determined by X-ray diffraction methods and refined by full-matrix least-squares to the conventional RW index of 0.074. The HgC bond length was fixed at 2.06 A in the final refinement, which gave a mean value of 2.33(3) A for the HgCl bond length.

Trimercurated acetaldehyde as the mercuration product of ethanol. The crystal structure of (ClHg)3CCHO·DMF and (BrHg)3CCHO·DMSO

Abstract The product obtained by boiling an ethanolic solution of mercuric chloride with sodium acetate (Hofmann, 1899) has been identified as tris(chloromercuri)acetaldehyde. The analogous bromomercuri derivative is obtained by using mercuric bromide. Both compounds crystallize from DMSO of DMF solution as the one-to-one solvates. The crystal structure of (ClHg)3CCHO·DMF (A) and (BrHg)3CCHO·DMSO (B) has been determined by X-ray diffraction methods and refined by full-matrix least-squares to the conventional R indices of 0.087 and 0.079, respectively. The mean value of the HgC bond length is 2.09(9) A in A and 2.04(7) A in B.

Notes. Preparation and crystal structure of hexa-µ-acetato-dichlorodi-µ3-oxotetraoxotetramolybdenum(V)–acetic anhydride (1/1)

Crystals of the title complex are monoclinic, with a= 14.992(5), b= 12.720(4), c= 17.536(6)A, β= 101.46(2)° space group C2/c, and Z= 4. The intensities of 4 603 reflections collected on an automatic diffractometer have been used to solve and refine the structure to R 0.036. The tetranuclear complex molecule, which has four molybdenum atoms bridged through two oxo-groups and six bidentate acetato-ligands, is located on a two-fold axis. Two of the four molybdenum atoms have Mo–Mo 2.609 A.

Molybdenum(V) complexes with monothio-β-diketones: thiodipivaloylmethane, thiodibenzoylmethane and benzoylthioacetone

The preparations of oxomolybdenum(V) complexes with thiodipivaloylmethane (Htdpm), [Mo2O3(tdpm)4]1 and [But2C3HS2][MoO(SH)3(tdpm)]2, thiodibenzoylmethane (Htdbm), [Mo2O3(tdpm)4]3, and both benzoylacetone (Hba) and benzoylthioacetone (Hbta), [Mo2O3(ba)3(bta)]4, are described. Crystal structures of 1 and 2 have been determined by X-ray diffraction techniques. Complex 1 is dinuclear, the anion of 2 mononuclear, both containing the molybdenum atoms in distorted-octahedral geometry. The charge transfer between the cation and anion of 2 is associated with close contacts between both the dithiolylium sulfurs and the SH-sulfur atom S(3)[S ⋯ S 3.335(2) and 3.515(2)A].

Mercury(II) complex with terpyridine : structure of the 2:1 solvate of [Hg(terpy)2](CF3SO3)2 with acetone

Abstract[Hg(terpy)2](CF3SO3)2·0.5(CH3)2CO crystallizes in the triclinic