Crystal structures of rac- and meso-o-Phenylenebis(iodomethylarsine), the latter as its lattice complex with the methiodide of 1,3-Dimethyl-1,3-dihydro-2,1,3-benzoxadiarsole

1977 ◽  
Vol 30 (11) ◽  
pp. 2417 ◽  
Author(s):  
K Henrick ◽  
CL Raston ◽  
AH White ◽  
SB Wild

The crystal structures of the title compounds, o-C6H4(AsMeI)2 (1), and o- C6H4(AsMeI)2- [o-C6H4(AsMe)(As+Me2)O] I- (2), have been determined at 295 K by single-crystal X-ray diffraction and refined by least squares to residuals of 0.037 and 0.067 for 2095 and 2913 reflections respectively. Crystals of (1) are triclinic, Pī, a 9.865(5), b 9.837(7), c 7.765(4) Ǻ, α 98.89(5), β 96.71(4), γ 60.72(4)�, Z 2. <As- I> is 2.585 Ǻ and <As-C> 1.97 Ǻ. The angles about the arsenic differ only trivially, the mean being 98.4�. Crystals of (2) are monoclinic, P21/n, a 15.315(4), b 21.511(8), c 7.952(2) Ǻ, β 98.19(2)�, Z 4. In the cation As-O distances are unequal [1.75(1) (quaternary As), 1.86(2) Ǻ]; As-O-As is very small being 115.8(8)�. Charge-transfer interactions between iodine species are present in both derivatives; in (2), there is an interaction between the tertiary arsenics of the meso molecule and the iodide anion, As...I being 3.307(3), 3.551(3) Ǻ, with the geometry of the arsenics approaching that of a tetrahedral disposition. Within the cation, the geometry about the quaternary arsenic is typical of arsenic(v), the bond lengths being shorter than those about the ternary arsenic.

1980 ◽  
Vol 33 (2) ◽  
pp. 313 ◽  
Author(s):  
PR Jefferies ◽  
BW Skelton ◽  
B Walter ◽  
AH White

Following the suggestion made earlier, on the basis of solution spectroscopy, that a number of eriostyl/nitrobenzoate compounds form charge-transfer self-complexes, a number of these have been investigated structurally by single-crystal X-ray diffraction methods in order to ascertain the presence or otherwise of such interactions in the solid state. The substances thus studied were eriostyl 3,5-dinitrobenzoate (1), eriostyl p-nitrobenzoate (2), tetrahydroeriostyl 3,5-dinitrobenzoate (3), and eriostemyl 3,5-dinitrobenzoate (4);* structure determinations in all cases, although displaying the presence of strong charge-transfer interactions from the two moieties of each molecule, show that the interactions in the solid state are intermolecular in nature.


1990 ◽  
Vol 43 (10) ◽  
pp. 1697 ◽  
Author(s):  
GA Bowmaker ◽  
PC Healy ◽  
LM Engelhardt ◽  
JD Kildea ◽  
BW Skelton ◽  
...  

The crystal structures of [Cu(Pme3)4]X (X = Cl , Br, I) and of [M(PPh3)4] [PF6] (M = Cu, Ag) have been determined by single-crystal X-ray diffraction methods at 295 K. The former compounds contain nearly tetrahedral [Cu(PMe3)4]+ ions on sites of m symmetry with mean Cu-P bond lengths of 2.270, 2.271 and 2.278 Ǻ for X = Cl , Br and I respectively. The latter compounds contain [M(PPh3)4]+ ions on sites of 3 symmetry. In the M =Ag complex the coordination environment is close to tetrahedral, but in the M =Cu complex the length of the axial Cu-P bond [2.465(2)Ǻ] is significantly shorter than that of the off-axis bonds [2.566(2)Ǻ]. Possible reasons for this are discussed.


1988 ◽  
Vol 43 (2) ◽  
pp. 171-174 ◽  
Author(s):  
Siegfried Pohl ◽  
Wolfgang Saak ◽  
Peter Stolz

(Ph4P)2Mn2Br6 (1) and (Ph3PCH2Ph)2Mn2I6 (2) were prepared from the reaction of manganese dihalide with the corresponding phosphonium halide in CH2Cl2.The structures of 1 and 2 were determined from single crystal X-ray diffraction data.Both compounds crystallize in the triclinic space group P 1 with one formula unit per unit cell.1:a = 998.1(1), b = 1005.7(1), c = 1313.3(2) pm, α = 108.51(1), β = 94.25(1), γ = 100.36(1)°.2: a = 1058.6(2), b = 1236.3(2), c = 1248.4(3) pm, α = 63.53(1), β = 74.15(1), γ = 74.65(1)°.The structures of 1 and 2 exhibit discrete, dimeric anions formed by the fusion of two identical tetrahedral-like units with a common halogen-halogen edge. The mean Mn-Hal bond lengths were found to be 251.8 pm (Mn-Br) and 272.2 pm (Mn-I). The difference between the bridging and terminal Mn-Hal bond lengths is about 12-13 pm in both compounds


1984 ◽  
Vol 37 (8) ◽  
pp. 1763
Author(s):  
IR Castleden ◽  
LM Engelhardt ◽  
SR Hall ◽  
AH White

The crystal structure of 8-hydroxy-1H-naphtho[2,1,8-mna]xanthen-1-one, C19H10O3, obtained as an indefinite methanolsolvate, has been determined at 295K by single-crystal X-ray diffraction methods, being refined by full matrix least squares to a residual of 0.056 for 892 independent 'observed' reflections. Crystals are monoclinic, P21/c, a 5.128(4), b 10.024(9), c 27.45(2) �, β 107.73(6)�, Z 4. The packing of the molecules is typically that of charge-transfer complexes, with an interplanar spacing of c.3.5 �.


1984 ◽  
Vol 37 (5) ◽  
pp. 921 ◽  
Author(s):  
PC Healy ◽  
JM Patrick ◽  
AH White

The crystal structures of the title compounds, [Ni(OH2)4(en)] [SO4].2H2O, (1), and [Ni(OH2)4(bpy)]- [SO4].2H2O, (2), have been determined by single-crystal X-ray diffraction methods at 295 K, being refined by full matrix least-squares methods to residuals of 0.028,0.031 for 1852, 4323 independent 'observed' reflections respectively. Crystals of (1) are monoclinic, C2/c, a 9.459(4), b 12.192(7), c 12.294(3) �, β 119.84(4)�, Z 4. In the cation, Ni-N is 2.061(2) �; Ni-O (trans to O, N respectively) are 2.106(2), 2.063(2) �. Instead of being enlarged above 90� as predicted from repulsion theory, the angle between the pair of oxygen atoms trans to nitrogen is diminished, being 87 14(7)�. Crystals of (2) are triclinic, P1, a 11.476(5), b 9.351(5), c 7.793(4) �, α 77.63(4), β 83.52(3), γ87.40(4)�, Z 2. In the cation, Ni-N are both 2.063(2) �. Ni-O (trans to N, O respectively) are 2.060(2), 2.O42(2); 2.O80(2), 2�. The short Ni-O distance [2.042(2)�] is associated with the coordination of a trigonal water molecule.


1973 ◽  
Vol 51 (13) ◽  
pp. 2073-2076 ◽  
Author(s):  
I. D. Brown ◽  
C. J. L. Lock ◽  
Che'ng Wan

One of the compounds obtained by reacting acetylacetone with oxoethoxodichlorobis(triphenylphosphine)rhenium(V) has been shown by single crystal X-ray diffraction to be trans-dichlorobis(pentane-2,4-dionato)rhenium(IV). The crystals are triclinic, a = 8.032(4), b = 8.344(6), c = 7.429(6) Å, α = 118.1(2), β = 92.3(2), γ = 55.5(2)°, [Formula: see text], Z = 1. Intensities were measured with a microdensitometer from photographs recorded on an integrating precession camera. Of the 991 measured reflections all were observed and 984 were used in the refinement. The structure was refined by full matrix least squares to an R2 value of 0.0685. The compound was found to be a trans-monomer, in contrast to the dimeric structure claimed to exist in solution. The ligand atoms bonded to rhenium lie almost exactly at the apices of an octahedron and the bond lengths (Re—Cl, 2.326(8); Re—O1, 1.97(1); Re—O2, 2.01(1) Å) are in the range expected.


1978 ◽  
Vol 31 (2) ◽  
pp. 285 ◽  
Author(s):  
GA Bottomley ◽  
LG Glossop ◽  
CL Raston ◽  
AH White ◽  
AC Willis

The crystal structures of [(en)2NiCl2Ni(en)2] Cl2 (1) and [(en)2NiCl2Ni(en)2] (ClO4)2 (2) have been redetermined from single- crystal X-ray diffraction data at 295(1) K and refined by least squares to residuals of 0.073 and 0.052 respectively for 1345 and 1605 'observed' reflections respectively. Crystals of (1) are monoclinic, P21/n, a 14.053(4), b 11.309(3), c 6.326(1) Ǻ, β 94.22(2)�, Z 2. Crystals of (2) are monoclinic, P21/n, a 8.885(12), 6 19.707(20), c 7.120(8) Ǻ, β 108.99(4)�, Z 2. In both (1) and (2), a dimeric complex cation is observed, a pair of cis coordination sites about the nickel in each case being occupied by the bridging chlorines; the latter are asymmetric (Ni-Cl, 2.461(3), 2.551(3)(1); 2.461(3), 2.512(3) Ǻ (2)).


1984 ◽  
Vol 37 (11) ◽  
pp. 2193 ◽  
Author(s):  
LM Engelhardt ◽  
JM Patrick ◽  
CL Raston ◽  
P Twiss ◽  
AH White

The crystal structures of the title compounds have been established by single-crystal X-ray diffraction techniques at 295 K, being refined by least squares to residuals of 0.043, 0.036, 0.036 for 2057, 3176 and 3468 independent 'observed' reflections respectively. Crystals of [Pd(diphos)2] C12 (1) (diphos = Ph2P(CH2)2PPh2) are monoclinic, P21/c, with a 12.779(9), b 18.084(10), c 12.942(6) �, β 119.29(5)�, 22; for the isostructural platinum analogue (2), a 12.789(4), b 18.099(7), c 12.965(4) �, β 1l9.39(2)�. Crystals of [PtCl2(diphos)].CH2Cl2, (3), are orthorhombic, P212121, with a 21.360(6), b 13.499(4), c 9.551(5)� Z 4. Complexes (1) and (2) are also solvated but the nature of the solvation is complicated by disorder and less clearcut than in (3). In (1), Pd-P distances are 2.342(2), 2.347(2) � in a centrosymmetric molecule; in (2), Pt-P distances are 2.332(2), 2.335(2) �, while in (3), Pt-P distances are 2.230(2), 2.224(3) � and Pt-Cl are both 2.355(2) � [cf. 2.233(2), 2.226(2), (2.361(2), 2.357(2))� respectively for the previously studied palladium analogue].


1983 ◽  
Vol 38 (12) ◽  
pp. 1615-1621 ◽  
Author(s):  
Annegret Lipka

2,2′-Bipyridinium pentachloroantimonate (III) and the metastable modification of 4,4′-bipyridinium pentachloroantimonate(III) were synthezised and investigated by single crystal X-ray diffraction analysis. The structures consist of 2,2′-bipyridinium and 4,4′-bipyridinium cations, respectively, and of pentachloroantimonate anions. With regard to bonding and short intermolecular contacts the coordination of the Sb atoms is distorted octahedral in both structures. Bond lengths of equivalent Sb-Cl bonds differ strongly within the structure of the 2,2′-bipyridinium salt (239.9 pm to 312.1 pm) and are not distinguishable from short intermolecular contacts (305.4 pm and 321.8 pm). In the structure of the 4,4′-bipyridinium salt, bond distances vary only from 240.9 pm to 267.8 pm and are clearly below intermolecular contacts at 318.2 pm. In spite of the different distances the total bond order for each Sb atom is 3. In the structure of the 2,2′-bipyridinium salt the anions build tetramers, whereas in the structure of the 4,4′-bipyridinium salt the anions form chains


1995 ◽  
Vol 50 (9) ◽  
pp. 1281-1286 ◽  
Author(s):  
Klaus Kopka ◽  
Rainer Mattes

AbstractThe complexes [(μ-PhCONNCOPh){VOCl(NHNHCOPh)}2 ·5CH3CN, (1), [(μ-PhCONNCOPh){V(dbh)}2]-2CH3CN, (2) and [{VO}2(tbh)], (3) have been prepared by reaction of VCl2(acac)2, acac = acetylaceto n a to (l-), and VCl2(acpn), acpn = propylendiim ino-bis(acetylacetonato(2-)), with benzoylhydrazine. The structures of the centrosymmetric dimeric molecules 1 -3 have been determined by single crystal X-ray diffraction. 1 and 2 contain both doubly deprotonated N,N′-dibenzoylhydrazine as bridging, doubly N,O chelating ligand. In 1 the two remaining coordination sites at the VOCl group are occupied by the hydrazid o(1-) ligand [NHNHCOPh]- . 2 is a non-oxo vanadium(IV) complex. The coordination geometry is approximately trigonal prismatic. The π-back donating effect of the oxo function is substituted by back donation from three negatively charged enolic oxygen atoms. The V - O bond lengths range from 192.0(2) to 193.7(2) pm. 3 contains a unique highly symmetrical octadentate ligand, formed during the synthesis. It is coordinated to two oxovanadin(IV) centers by N,O chelation. The coordination geometry is square pyramidal.


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