Organoamido- and Aryloxo-Lanthanoids. II. Preparation of Tris(2,6-diphenylphenoxo)-lanthanoid(III) Complexes and the X-Ray Structures of Low-Coordinate [Yb(O-2,6-Ph2C6H3)3] Containing an Intramolecular Chelate Yb…π-Arene Interaction, and [Yb(O-2,6-Ph2C6H3)3(thf)2].thf (thf = Tetrahydrofuran)

1990 ◽  
Vol 43 (7) ◽  
pp. 1245 ◽  
Author(s):  
GB Deacon ◽  
S Nickel ◽  
P Mackinnon ◽  
ERT Tiekink

Bulky monomeric lanthanoid(III) aryl oxides Ln(Odpp)3(Odpp = 2,6- diphenylphenoxide; Ln = Nd, Sm, Er, Yb or Lu) have been prepared by reaction between the lanthanoid metal, Hg(C6F5)2, and HOdpp in tetrahydrofuran (thf), and Yb(Odpp)3 has also been obtained from an analogous reaction of (PhCC)2Hg. Cleavage of Ln(η5-C5H5)3 (Ln = Nd or Yb) with HOdpp also yields Ln(Opdd)3. The aryl oxides have been isolated as [Ln(Odpp)3(thf)2] (Ln = Nd, Sm or Yb) or as the homoleptic complexes Ln(Odpp)3 (Ln = Nd, Er, Yb or Lu). The X-ray crystal structure of [Yb(Odpp)3(thf)2].thf [crystals monoclinic, space group P21/n, a 11.009(4), b 32.134 (7), c 15.498(6)Ǻ, β 96.72(3)°, Z 4; 2785 data refined to R 0.039] shows the complex to have distorted square pyramidal stereochemistry with apical and transoid basal Odpp ligands, (Yb-Odpp) 2.078(9)Ǻ, and transoid basal thf ligands, {Yb-O(thf)} 2.305(8)Ǻ. Similarly, Yb(Odpp)3 [crystals triclinic, space group Pī, a 15.934(2), b 13.563(1), c 10.968(2)Ǻ, α 116.71(1), β 92.90(2), γ 103.38(1)°, Z 2; 6236 data refined to R 0.031] was shown to have a trigonal pyramidal arrangement of oxygen donor atoms [{Yb-O} 2.065(4) Ǻ;{O-Yb-O} 117.5(1)°], a novel intramolecular chelate Yb…π-arene interaction, {Yb...C} 2.978(6)Ǻ, and an agostic Yb…CH interaction.

1993 ◽  
Vol 46 (12) ◽  
pp. 1881 ◽  
Author(s):  
JE Cosgriff ◽  
GB Deacon ◽  
BM Gatehouse

From reaction of lanthanoid metals with bis ( pentafluorophenyl )mercury and 3,5-diphenylpyrazole (HPh2pz) in 1,2-dimethoxyethane ( dme ) and treatment of the products with triphenylphosphine oxide, the complexes [ Ln (η2-Ph2pz)3(OPPh3)2].( dme )n ( Ln = Er or Nd , n = 1; Ln = La, n = 0.6) have been isolated. An X-ray crystal structure shows that the erbium complex [monoclinic, space group C2, a 22.08(3), b 14.30(1), c 13.37(1) Ǻ, β 124.09(7)°, Z 2 2730 'observed' data refined to R 0.046] is monomeric , with eight coordination of the metal. There is a trigonal bipyramidal arrangement of the centre ( Cen ) of the N-N bonds of three η2-3,5-diphenylpyrazolate groups ( ΣCen-Er-Cen 360°; ( Er -N) 2.344 Ǻ) and the oxygens of two equivalent trans triphenylphosphine oxide ligands [O- Er -O 176(1)°; Er -O 2.207(9)Ǻ]. Unit cell data indicate that the neodymium analogue [monoclinic, space group C2, a 23.01(3), b 14.94(2), c 13.82(2) Ǻ, β 123.65(8)°] is isostructural with the erbium complex. An analogous reaction of lanthanum or neodymium metal, Hg(C6F5)2, and HPh2pz in tetrahydrofuran ( thf ) gives [ Ln (η2-Ph2pz)3( thf )3]. thf ( Ln = La or Nd ). The X-ray crystal structure of the neodymium complex [orthorhombic, space group P212121, a 14.009(9), b 16.280(8), c 22.640(16)Ǻ, Z 4, 2967 'observed' data refined to R 0.046 reveals a nine-coordinate monomer with three η2-Ph2pz ligands [ Nd -N 2.420(10)-2.524(8)Ǻ] and three thf ligands [ Nd -O 2.497(8)-2.587(8)Ǻ]. There is a trigonal prismatic arrangement of the centres of the N-N bonds and the oxygen donor atoms.


1977 ◽  
Vol 30 (11) ◽  
pp. 2395 ◽  
Author(s):  
R Mason ◽  
GR Scollary

X-ray diffraction analysis of the two complexes [CoPhP{(CH2)3PPh2}2P(OMe)3CO] BF4,thf and [CoPhP{(CH2)2PPh2}2{P(OMe)3}2] BF4 are reported. Crystals of the first complex are triclinic, space group Pī with a 14.310(1), b 11.080(2), c 16.099(3) Ǻ, α 68.30(2), β 90.78(2), γ 75.04(1)�. The structure analysis has been based on 2964 independent reflection intensities (Cu Kα automatic diffractometry) to give R 0.11. The second complex is monoclinic, space group P21/c, with a 13.18(4), b 11.49(3), c 29.66(6) Ǻ, β 101.59(2)�. Refinement by least squares has converged to R 0.093 for the 2256 independent reflection intensities, observed by Mo Kα automatic diffractometry. The preferred stereochemistries of the five-coordinate cobalt complexes are discussed in relation to the bite angle of the chelating phosphine.


1986 ◽  
Vol 41 (11) ◽  
pp. 1420-1425 ◽  
Author(s):  
Ruth Christophersen ◽  
Wolfgang Willing ◽  
Ulrich Müller ◽  
Kurt Dehnicke

Abstract β-VCl2(N3S2) was obtained by sublimation. It represents a new modification compared to the known α-VCl2(N3S2) which can be obtained from solution. Its crystal structure was determined by X-ray diffraction (864 observed reflexions, R = 0.034). Crystal data: triclinic, space group P1̄, Z = 2, a = 570.0, b = 779.9, c = 735.3 pm , α = 90.85°, β = 108.26°, y = 98.77°. Both modifications consist of polymer chains in which the vanadium atoms are linked alternatively by chloro and nitrogen bridges. The packing of the chains is rather similar, the only difference being that in β-VCl2(N3S2) the chains are rotated by 11° as compared to the orientation in α-VCl2(N3S2). The difference of the two modifications also shows up in the slightly different IR spectra. By reduction of VCl2(N3S2), dissolved in CH2Cl2/pyridine, with H2S, zinc or PPh3, the cyclothiazeno complex [VCl(N3S2)(pyridine)2]2·2 CH2Cl2 was obtained. It crystallizes in the monoclinic space group P 21/c, Z = 4, a = 1010.4, b = 917.3, c = 1967.8 pm, β = 103.03° (structure determination with 649 observed reflexions. R = 0.081). In this vanadium(IV) compound the metal atoms are part of planar VN3S2 rings as found in the VCl2(N3S2) modifications. The two vanadium atoms of the centrosymmetrical dimer are linked via one nitrogen atom of each of the VN3S2 rings; the resulting V2N2 ring is coplanar with the two VN3S2 rings.


1988 ◽  
Vol 43 (3) ◽  
pp. 289-294 ◽  
Author(s):  
Wolfgang Saak ◽  
Detlev Haase ◽  
Siegfried Pohl

The reaction of FeI2, with (Me3NCH2Ph)I in CH2Cl2 and with Ph3PS in toluene (molar ratios 1:1) yields (Me3NCH2Ph)2Fe2I6 (1) and Fe2I6(SPPh3)2·C6H5CH3 (2), respectively. The structures of 1 and 2 were determined from single crystal X-ray diffraction data. 1 crystallizes in the monoclinic space group P21/n with a = 895.7(2), b = 1400.5(2), c = 1360.6(3) pm. β = 95.82(2)°, Z = 2. The anion of 1, Fe2I62-, has edge-sharing double-tetrahedra. The bridging and terminal F e - I bond lengths were found to be 269.9/270.7 and 260.3/258.6 pm, respectively (Fe-Fe: 358.2 pm). 2 crystallizes in the triclinic space group P1̄ with a = 987.6(1), b = 1119.3(1), c = 1159.4(1) pm, α = 101.10(1), β = 99.15(1), γ = 102.83(1)°, Z = 1. The molecules of 2 consist of centrosymmetric dinuclear Fe2I2 units (like for Fe2I62- in 1), with F e - I distances of 266.4 and 273.4 pm. The distorted tetrahedra around Fe are completed by an iodide ion (Fe-I: 256.9 pm) and Ph3PS with the sulfur as donor atom. The Fe-Fe distance was found to be 339.7 pm.


1981 ◽  
Vol 36 (10) ◽  
pp. 1208-1210 ◽  
Author(s):  
Hartmut Köpf ◽  
Joachim Pickardt

Abstract The molecular structure of the bridged [1]-titanocenophane 1,1'-dimethylsilylene titanocene dichloride, (CH3)2Si(C5H4)2TiCl2, has been investigated by an X-ray structure determination. Crystal data: monoclinic, space group C2/c, Z = 4, a = 1332.9(3), 6 = 988.7(3), c = 1068.9(3) pm, β = 113.43(2)°. The results are compared with the structural dimensions of similar compounds: 1,1'-methylene titanocene dichloride, CH2(C5H4)TiCl2, with the unbridged titanocene dichloride, (C5H5)2TiCl2 and the ethylene-bridged compound (CH2)2(C5H4)2TiCl2


1995 ◽  
Vol 50 (7) ◽  
pp. 1018-1024 ◽  
Author(s):  
Axel Michalides ◽  
Dagmar Henschel ◽  
Armand Blaschette ◽  
Peter G. Jones

In a systematic search for supramolecular complexes involving all combinations of the cyclic polyethers 12-crown-4 (12C4), 15-crown-5 (15C 5), 18-crown-6 (18C 6) and dibenzo- 18-crown-6 (DB -18C6), and the geminal di- or trisulfones H2C(SO 2Me)2, H2C (SO2Et)2 and HC (SO2Me)3-n (SO2Et)n (n = 0 -3 ) , only the following four complexes could be isolated and unequivocally characterized by elemental analysis and 1H NMR spectroscopy: [(12C4){H2C (SO2Et)2}2] (3), [(18C6){H2C (S O2Me)2}] (4), [(DB -18C 6){H2C (SO2Et)2}] (5) and [(D B -18C 6)2{HC (SO2Me )(SO2Et)2}3] (6). The structure of 3 (triclinic, space group P1̄) consists of crystallographically centrosymmetric formula units, in which the disulfone molecules are bonded on each side of the ring by two C -H ··· O(crown) interactions originating from the central methylene group (H···O 213 pm) and from the methylene group of one EtSO2 moiety ( H ··· O 237 pm). Formula units related by translation are connected into parallel strands by a third type of reciprocal C -H ···O bond (H ···O 232 pm) between the second H atom of the central methylene group and a sulfonyl oxygen atom of the adjacent unit. The structure of 4 (monoclinic, space group C2/c) showed severe disorder of the crown ether and could not be refined satisfactorily. Compounds 5 and 6 crystallized as long and extremely thin fibres, indicative of linear-polymeric supramolecular structures; single crystals for X-ray crystallography were not available.


1983 ◽  
Vol 36 (11) ◽  
pp. 2333 ◽  
Author(s):  
B Kamenar ◽  
RA Pauptit ◽  
JM Waters

The X-ray crystal structure of 3α,4α:5β,6β-diepoxyandrostan-17-one has been determined. Crystals of the title compound (C19H26O3)are monoclinic, space group P21, with a 9.208(2), b 9.620(4), c 9.312(3) �, β 99.14(2)�, V 814.5 Ǻ3 and Z 2. The structure was solved by direct methods and refined to R 0.039 for 887 observed reflexions. The 3α,4α:5β,6β configuration of the epoxide rings confirms the assignment based on proton n.m.r. studies.


2005 ◽  
Vol 60 (9) ◽  
pp. 978-983 ◽  
Author(s):  
Sevim Hamamci ◽  
Veysel T. Yilmaz ◽  
William T. A. Harrison

Two new saccharinato-silver(I) (sac) complexes, [Ag(sac)(ampy)] (1), and [Ag2(sac)2(μ-aepy)2] (2), [ampy = 2-(aminomethyl)pyridine, aepy = 2-(2-aminoethyl)pyridine], have been prepared and characterized by elemental analysis, IR spectroscopy, thermal analysis and single crystal X-ray diffraction. Complexes 1 and 2 crystallize in the monoclinic space group P21/c and triclinic space group P1̄, respectively. The silver(I) ions in both complexes 1 and 2 exhibit a distorted T-shaped AgN3 coordination geometry. 1 consists of individual molecules connected into chains by N-H···O hydrogen bonds. There are two crystallographically distinct dimers in the unit cell of 2 and in each dimer, the aepy ligands act as a bridge between two silver(I) centers, resulting in short argentophilic contacts [Ag1···Ag1 = 3.0199(4) Å and Ag2···Ag2 = 2.9894(4) Å ]. Symmetry equivalent dimers of 2 are connected by N-H···O hydrogen bonds into chains, which are further linked by aromatic π(py)···π(py) stacking interactions into sheets.


1993 ◽  
Vol 48 (12) ◽  
pp. 1727-1731 ◽  
Author(s):  
A. Franken ◽  
W. Preetz ◽  
M. Rath ◽  
K.-F. Hesse

By electrochemical oxidation of [B6H6]2- in the presence of nitrite ions and the base DBU in dichloromethane solution mononitropentahydrohexaborate [B6H5(NO2)]2- ions are formed and can be isolated by ion exchange chromatography on diethylaminoethyl cellulose. The crystal structures of the K and Cs salt were determined from single crystal X-ray diffraction analyses. K2[B6H5(NO2)] is monoclinic, space group P21/m with a = 5.953(1), b = 8.059(4), c = 8.906(1) Å, β = 109.553(9)°; Cs2[B6H5(NO2)] is monoclinic, space group P21/a with a = 9.438(6), b = 9.644(7), c = 11.138(9) Å, β = 101.44(9)°. The B6 octahedron is compressed in the direction of the B—NO2 bond by about 5%, with bond lengths between 1.67 and 1.77 A.


2002 ◽  
Vol 57 (1) ◽  
pp. 43-46 ◽  
Author(s):  
Beatriz S. Parajón-Costaa ◽  
Enrique J. Baran ◽  
Oscar E. Piro ◽  
Eduardo E Castellano

The crystal structure of [Cu(sac)2(nic)2(H2O)] (sac = saccharinate anion; nic = nicotinamide) has been determined by single-crystal X-ray diffraction. It crystallizes in the monoclinic space group C2/c with Z = 4 and the Cu(II) ion presents a CuN4O square pyramidal coordination. Some comparisons with related structures are made and the most important features of its IR spectrum were also discussed.


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