Anthony J. Edwards

Heteroleptic polypyrazolylborate derivatives of the lanthanide ions. The synthesis of acetylacetonate derivatives and the molecular structures of [Ln{HB(C3N2H3)3}2{MeC(O)CHC(O)Me}] (Ln = Ce, Yb)

Abstract The air and moisture stable complexes [Ln{HB(C3N2H3)3}2{MeC(O)CHC(O)Me}] (Ln = La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Yb, Lu, Y), have been prepared and characterized. The molecular structures of the compounds with Ln = Ce and Yb reveal that a substantial distortion of the coordination geometry found for Ce3+ is necessary to allow the ligand set to accommodate the smaller Yb3+ ion.

Metal complexes of N-aryl-N-nitrosohydroxylamines: cleavage of N–N bonds to give metal nitrosyl species and organonitrogen compounds, and the crystal structure of [RhCl2{ONN(C6H4Me-p)O}(H2O)(PPh3)]·0.5Me2CO

Reaction of [RhCl(PPh3)3], [Rh2(CO)4Cl2], [Rh2(η-C5Me5)2Cl4], [RuCl2(PPh3)3], and [Pd(Ph)Cl(PPh3)2] with Q[ONN(R)O](Q = NH4 or Ag; R = Ph or C6H4Me-p) afforded [RhL2{ONN(R)O}](L = PPh3 or CO), [Rh(η-C5Me5)Cl{ONN(R)O}], [Ru{ONN(R)O}2(PPh3)2], and [PdPh{ONN(R)O}(PPh3)]. Reaction of [Rh{ONN(R)O}(PPh3)2] with I2 gave [{Rhlx[ONN(R)O](PPh3)2}n](R = Ph, x= 2, n= 1; R = C6H4Me-p, x= 1, n= unknown), and with CO gave [Rh(CO){ONN(R)O}(PPh3)]. The latter was also prepared from [Rh(CO)2{ONN(R)O}] and PPh3. Treatment of [Rh{ONN(R)O}(PPh3)2] and [Ru{ONN(R)O}2(PPh3)2] with RhCl3 and RuCl3 afforded [RhCl2{ONN(R)O}(H2O)(PPh3)] and [RuCl{ONN(R)O}2(PPh3)2], respectively. The structure of [RhCl2{ONN(C6H4Me-p)O}(H2O)(PPh3)]·0.5Me2CO was determined crystallographically, and the metal shown to be six-co-ordinate with a chelating N-aryl-N-nitrosohydroxylminato ligand and water. Treatment of [PdPh{ONN(R)O}(PPh3)], [Rh{ONN(C6H4Me-p)O}(PPh3)2], and [Ru{ONN(C6H4Me-p)O}2(PPh3)2] with HCl gave [Pd2Cl4(PPh3)2], [RhCl2(NO)(PPh3)2], and [RuCl3(NO)(PPh3)2], respectively, and the organic products obtained from the complexes of Rh and Ru identified by gas chromatography and mass spectrometry as p-MeC6H4NO, p-MeC6H4NH2(major component), and C6H3Me(NH2)Cl. A possible mechanism of formation of the nitrosyl complexes and organonitrogen compounds is briefly discussed.

Fluoride crystal structures. Part 33. Tetraethylammonium µ-fluoro-bis[oxoperoxo(pyridine-2,6-dicarboxylato)molybdate(VI)]

The structure of the title compound has been determined by the heavy-atom method from 2 417 reflections, measured with a diffractometer, and refined by full-matrix least-squares methods to R.0.044. Crystals are monoclinic, space group C2/c, with unit cell dimensions a= 18.55(2), b= 12.43(2), c= 14.17(2)A, and β= 119.1(3)°. In the structure each molybdenum atom has a pentagonal-bipyramidal co-ordination, with the centrosymmetric binuclear anions formed by axially linking two units, through a symmetric fluorine bridge. The Mo–F distance of 2.135 A is very long, due to the trans effect of the oxide ligand (Mo–O 1.659 A) and to the bridging role of the fluorine atom.

The ‘bare’ Sn2+ ion. X-Ray crystal structure and Mössbauer spectrum of (Sn2+)-(SbF6–)2(AsF3)2

The 119Sn Mossbauer spectrum of the title compound shows the highest isomer shift, with no detectable quadrupole splitting, so far recorded for a tin(II) species and the crystal structure reveals a nine co-ordinate arrangement of fluorine atoms around the tin atom, with a distortion in geometry compatible with the presence of the lone pair of electrons.

Fluoride crystal structures. Part 30. 2,2′-Bipyridylfluorodioxovanadium(V)

The structure of the title compound has been determined from X-ray diffractometer data and refined by full-matrix least-squares methods to R 0.078 for 1 084 reflections. Crystals are monoclinic, space group P21/c, a= 6.43, b= 15.80, c= 13.94 A, β= 134.8°. The vanadium atom has a distorted square pyramidal arrangement and achieves a distorted octahedral co-ordination by weak dimer formation, through asymmetric oxygen bridges. The vanadium–oxygen distances are V–O (terminal) 1.618(8) and V–O (bridge) 1.691(7) and 2.361(7)A.

Fluoride crystal structures. Part 28. Bis(tetraethylammonium)µ-oxo-bis[pentafluorotantalate(V)]

The structure of the title compound has been determined by the heavy-atom method from 1 267 reflections, measured with a diffractometer, and refined by full-matrix least-squares methods to R 0.069. Crystals are monoclinic, space group P21/n, a= 8.57(1), b= 13.68(2), c= 11.79(2)A, β= 96.1 (1)°, Z= 2. In the structure two tetraethylammonium ions counterbalance each [Ta2OF10]2– complex anion in which the two tantalum atoms are bridged by an oxygen atom (Ta–O 1.875 A; Ta–O–Ta 180° by symmetry); the five remaining octahedral sites around each tantalum atom are occupied by fluorine atoms (mean Ta–F 1.90 A).

μ-Fluoro complexes peroxydes du molybdene VI

Resume A Mo-F-Mo bridge is obtained in seven coordinated oxoperoxomolybdate VI complexes with formula M I {Mo 2 O 2 (O-O) 2 (dipic) 2 F} M I ={(C 2 H 5 ) 4 N} + , {(CH 3 ) 4 N} + , Cs + , Rb + , K + , Na + -(dipic) = {(C 7 H 3 NO 4 )} 2- . The anion is mononuclear with M I = NH + 4 and when the halogenoligand is Cl.

Alkoxy, thiophenolato and amido complexes of molybdenum tris-(3,5-dimethylpyrazolyl)borato nitrosyl acetate and benzoate, and the X-ray crystal structure of Mo{HB(3,5-Me2C3HN2)3}(NO)(NHPh)(OCOMe)·2CHCl3

Abstract The complexes MoL*(NO)(OR)(OCOR′) (L* = HB(3,5-Me 2 C 3 HN 2 ) 3 ; R = Me, Et, Pr n , Pr i ; R′= Me, Ph: R = CH 2 CH 2 OH, OH; R′= Ph: R = Ph, C 6 H 4 OMe- p ; R′= Me, Ph: R = C 6 H 4 Me-p; R′= Me), MoL*(NO)(SPh)(OCOR′) (R = Me or Ph) and MoL*(NO)(NHR)(OCOR′) (R = Me, Et, Ph; R′ = Me, Ph) were prepared by reaction of MoL*(NO)I(OR), MoL*(NO)I(SPh) and MoL*(NO)I(NHR) with AgOCOMe or AgOCOPh. The IR spectra of these complexes indicated that the carboxylate groups are monodentate and this was confirmed by a single crystal X-ray structural determination of MoL*(NO)(NHPh)(OCOMe).

Steric and electronic effects on the chemistry of molybdenum octahedrally co-ordinated by six nitrogen atoms. The molecular structure of [Mo{HB(3,5-Me2C3N2H)3}(NO)(pyrollide)2]

[Mo{HB(3,5-Me2C3N2H)3}(No)I2] reacts with the nitrogen heterocycles Z to give [Mo{HB(3,5-Me2C3N2H)3}(NO)Z2]+, where Z = pyridine, imidazole, N-methylimidazole, or pyrazole, with monosidium organoamides to give [Mo{HB(3,5-Me2C3N2H)3}(NO)Y2] where Y = NHEt–, NHPh–, p-NHC6H4Me–, or pyrollide, and with moist tetrahydrofuran to give [Mo{HB(3,5-Me2C3N2H)3}(NO)I{O[CH2]4I}]; the molecular structure of [Mo{HB(3, 5-Me2C3N2H)3}(NO)-(pyrollide)2] has been determined.

Heteroleptic poly(pyrazolyl)borate derivatives of the lanthanide ions. The synthesis of acetylacetonate complexes and the molecular structures of [Ln{HB(C3N2H3)3)2(MeC(O)CHC(O)Me}](Ln = Ce or Yb)

The air- and moisture-stable complexes [Ln{HB(C3N2H3)3}2{MeC(O)CHC(O)Me}](Ln = La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb, Tm, Lu, or Y) have been prepared and characterised. Evidence was found that intramolecular ligand reorganisation processes were occurring on the n.m.r. time-scale down to –80 °C. The molecular structures of the compounds with Ln = Ce and Yb have been determined. Polytopal analysis of these structures reveals that a substantial distortion of the near bicapped trigonal prismatic co-ordination geometry, found for the cerium complex, towards square antiprismatic is necessary to allow the ligand set to accommodate the smaller Yb3+ ion.