Salih S. Al-Juaid

The synthesis and crystal structures of 1-phenyl-3-methyl-4-butanolypyrazol-5-one and of two pyrazolonato complexes of iron

Abstract An X-ray study showed that 1-phenyl-3-methyl-4-butanoylpyrazol-5-one, RCOC10 H9N2O (abH, R = Pr) (1), crystallized in the enol form. It reacted with iron(III) salts to give a dark red complexes, [Fe(ab)3], which crystallized from butanol as the mer-isomer. The complex [Fe(ab)3] (R = Me) was prepared similarly, but the fac-isomer was obtained.

New heptacoordinated tin complexes of 2,6-diacetylpyridine-bis(thiosemicarbazone), H2daptsc, and of 2,6-diacetylpyridine-bis(semicarbazone), H2dapsc. Crystal and molecular structures of [MeSnCl(Hdaptsc)]Cl·MeOH and [MeSnCl(H2dapsc)]Cl2·2H2O

Two new heptacoordinated organotin complexes, [MeSnCl(Hdaptsc)]Cl·MeOH (1) and MeSnCl(H2dapsc)]- Cl2·2H2O (2), have been prepared from MeSnCl3 and H2daptsc and H2dapsc, respectively. Single crystal X-ray diffraction studies showed them to be approximately pentagonal bipyramidal (PBP), with the organic ligands lying in the equatorial plane. H2daptsc and SnCl4 form a complex with the formula [ClSnCl(Hdaptsc)]Cl (3), which is presumed to have an analogous PBP structure. On the other hand, the complex obtained from H2dapsc and Me2SnCl2 is tentatively formulated as [(Me2SnCl2)2(H2dapsc)] (4), and 119Sn Mossbauer spectroscopic evidence suggests an octahedral coordination for the two tin atoms.

Pyrazolonato complexes of lead. Crystal structures of bis(1-phenyl-3-methyl-4-acetyl pyrazolonato)lead(II) and bis(1-phenyl-3-methyl-4-butanoylpyrazolonato)lead(II)

Abstract The structures of the complexes [PbL 2 ], L = 1-phenyl-3-methyl-4-acylpyrazolonato, RCOC 10 H 8 N 2 O, R = Me ( 2 ) or Pr ( 3 ), have been determined by X-ray diffraction studies. Compound 2 is monoclinic, space group P2 1 , a = 11.285(4), b = 14.727(4), c = 20.749(5) A , β = 95.83(3)°, R = 0.039 for 4486 reflections, and 3 is monoclinic, space group C2/c, a = 27.528(11), b = 7.245(11), c = 14.264(7) A , β = 113.6(3)°, R = 0.021 for 2118 reflections. There are three different lead environments in 2 but only one in 3 . In each case the lead atom makes four strong bonds to oxygen and two weaker bonds to either oxygen or nitrogen in adjacent molecules.

Hydrogen-bonding in organosilanetriols. The crystal structures of tris(trimethylsilyl)silyl- and tris(trimethylsilyl)-methyl-silanetriols

Abstract The organosilanetriols (Me 3 Si) 3 CSi(OH) 3 and (Me 3 Si) 3 SiSi(OH) 3 both crystallize as hexameric hydrogen-bonded cages with no hydrogen bonding between the cages. Both (Me 3 Si) 3 CSi(OH) 3 and (Me 3 Si) 3 SiSi(OH) 3 are remarkably thermally stable as solids, melting with decomposition only at 285–290 and 210–213°C, respectively.

Preparation and crystal structures of the crowded organotin fluorides (PhMe2Si)3CSnMe2F, (Me3Si)3CSnMe2F, and (Me3Si)3CSnPh2F

Abstract X-Ray diffraction studies have established that crystals of the organotin fluorides (Me 3 Si) 3 CSnMe 2 F, (Me 3 Si) 3 CSnPh 2 F, and (PhMe 2 Si) 3 CSnMe 2 F are made up of discrete molecules with no intermolecular F⋯Sn interactions. The data for (PhMe 2 Si) 3 CSnMe 2 F are of good quality ( R = 0.029, R′ = 0.040), and provide the first measurement of an SnF bond length (1.965(2) A) in a four-coordinate tin species.

The preparation and crystal structures of the compounds (Ph2MeSi)3CMCl (M Zn, Cd, or Hg)

The compounds (PhMe2Si)3CMCl (M  Zn, Cd, or Hg) have been prepared by reaction of (PhMe2Si)3CLi with the chlorides MCl2; for M  Zn or Cd they were obtained via (isolated) Li-containing intermediates thought to [(PhMe2Si)3CM(μ-Cl)2Li(THF)2]. The crystal structures of all three compounds [(PhMe2Si)3CMCl have been determined. The zinc and cadmium chlorides are present in the crystal as the dimers [(PhMe2Si)3CM(μ-Cl)2MC(SiMe2Ph)3], with the metals three-coordinate in a planar environment (for M  Zn, the CMCl angles average 136° and the ClMCl angles 88°; for M  Cd the corresponding values are 137° and 86°) and the chloride bridges slightly unsymmetrical. The cadmium compound is also dimeric in solution in benzene. The compounds appear to be the first structurally characterized organo-zinc or -cadmium halides in which the metal is three-coordinate. The mercury compound also forms dimers in the solid, but the geometry is almost that expected for two-coordinate mercury (the CHgCl angles at the two metal centres are 171.0(3) and 171.3(3)°), with a very weak intermolecular Hg⋯Cl interaction (mean distance 3.29 A). The conformations of the (PhMe2Si)3C groups in all three compounds are discussed.

Reactions of sterically hindered organozinc and organocadmium compounds containing functional silicon centres. Crystal structures of Zn[C(SiMe3)2(SiMe2OCOCF3)]2 and Cd[C(SiMe3)2(SiMe2OMe)]2

Abstract The compound (Me 3 Si) 2 CCl 2 was converted by treatment with BuLi/Et 2 O/THF and then with Me 2 HSiCl into (Me 3 Si 2 )CCl(SiMe 2 H). Further lithiation with BuLi gave LiC(SiMe 3 ) 2 (SiMe 2 H), which reacted with ZnBr 2 to yield Zn[C(SiMe 3 ) 2 (SiMe 2 H)] 2 . Thence, several new organozinc compounds Zn[C(SiMe 3 ) 2 (SiMe 2 X)] 2 , with X  Cl, Br, I, F, OH, OMe, O 2 CCF 3 , O 2 CH, or NCS, were obtained by substitutions at silicon without cleavage of ZnC bonds. The compounds Cd[C(SiMe 3 ) 2 (SiMe 2 X)] 2 , with X  H, OMe, and Ph, were obtained similarly, but subsequent substitutions at Si were accompanied by reactions at Cd. The crystal structure of the trifluoroacetato derivative Zn[C(SiMe 3 ) 2 (SiMe 2 OCOCF 3 )] 2 shows that the molecules are centrosymmetric, with the O 2 CCF 3 groups forced outwards by steric hindrance away from the metal centre. In Cd[C(SiMe 3 ) 2 (SiMe 2 OMe)] 2 , the methoxy groups are folded in towards cadmium but the Cd … O distance is only slightly shorter than the sum of the van der Waals radii.

Upon the hydrogen-bonding ability of the H4 and H5 protons of the imidazolium cation

The crystal and molecular structures of [Me2Etim]Cl, [Me2Etim]2[CoCl4], and [Me2Etim]2[NiCl4] ([Me2Etim]+ = 1,2-dimethyl-3-ethylimidazolium cation) all contain evidence that the H4 and H5 protons of the imidazolium cation enter into hydrogen bonds; the implications of this observation for the interactions in room-temperature chloroaluminate(III) ionic liquids are considered.

Some unusual organo-zinc and -mercury compounds. The crystal structures of the compounds [(HOMe2Si)(Me3Si)2C]2Zn, [(MeOMe2Si)(Me3Si)2C]2Zn, and [(MeOMe2Si)(Me3Si)2C]2Hg

The preparation of the novel mercurial [(MeOMe2Si)(Me3Si)2C]2Hg is described. X-ray diffraction studies show that the molecules of this compound and its zinc analogue are centrosymmetric (and the CMC linkage thus linear), but in the former OMe group is directed away from the metal atom whereas in the latter it lies in towards the metal, with an O⋯Zn distance of 2.93 A. In crystals of [(HOMe2Si)(Me3Si)2C]2Zn there is hydrogen bonding between the two oxygen atom within each molecule, and hydrogen bonding between two molecules to give discrete dimers. Because of the hydrogen bonding the CZnC linkage is slightly bent (the angle is 175.9(1)°), and the geometries of the two [(HOMe2Si)(Me3Si)2C]2C groups are significantly different.

Novel alkylmetal hydroxides. The crystal and molecular structures of bis(µ-hydroxy)-bis{tris(dimethylphenylsilyl)methylzinc}, [{Me2PhSi)3CZnOH}2] and µ4-oxohexa(µ-hydroxy)tetrakis{tris(trimethylsilyl)methylindium}, [O{(Me3Si)3Cln}4(OH)6]

The compounds [{(Me2PhSi)3CZnOH}2] and [O{(Me3Si)3Cln}4(OH)6] have been shown by X-ray diffraction to have structures based on four-membered M2O2-rings (M = Zn or ln).