Crystal-Structures of (Nh4)2(AgI3)∞/ ∞.H2O And (Nme4)(Ag2I3)∞/∞

1986 ◽  
Vol 39 (1) ◽  
pp. 171 ◽  
Author(s):  
JD Kildea ◽  
BW Skelton ◽  
AH White

Single-crystal X-ray structure determinations of the title compounds at 295 K are reported. For (1), (NH4)2(AgI3)∞/∞.H2O, the structure is isomorphous with that reported previously for K2AgI3, being orthorhombic, Pbnm , a 21.20(2), b 10.84(1), c 4.629(3)Ǻ, Z 4, R 0.032 for 1211 'observed' independent reflections. Locations and refinement of an artefact modelled as a water molecule raises the possibility that other members of the isomorphous series may be monohydrates rather than anhydrous. (NMe4)(Ag2I3)∞/∞, (2), is orthorhombic, Pnam , a 17.760(7), b 10.077(4), c 7.431(2)Ǻ, Z 4, R 0.043 for 977 'observed' independent reflections; the structure is a redetermination of better precision confirming the essential features of an earlier study and treating the cation in terms of an ordered rather than a disordered model.


2000 ◽  
Vol 53 (10) ◽  
pp. 875 ◽  
Author(s):  
Kevin C. Lim ◽  
Brian W. Skelton ◽  
Allan H. White

Low-temperature single-crystal X-ray structure determinations are recorded for the (‘maximally’) hydrated scandium(III) trihalides, ScX3.nH2O (X = Cl, Br, I). The chloride and bromide are isomorphous heptahydrates (n =7), ScX3.7H2O =[Sc(OH2)7]X3, monoclinic, space group P2/n, a ~ 7.6, b ~ 7.7, c ~ 9.6 Å, β ~ 99˚, Z = 2, R 0.051, 0.039 for No 1253, 1339 ‘observed’ (F > 4σ (F)) reflections, respectively, the metal atom disposed in a homoleptic environment of seven water molecule oxygen atoms arranged in an essentially pentagonal-bipyramidal disposition, site symmetry 2, Sc–O(axial) 2.095 Å, Sc–O(eq) 2.157(3)–2.209(4) Å. The iodide is an octahydrate, ScI3.8H2O =[Sc(OH2)7]I3.H2O, monoclinic P21/c, Z = 4, R 0.022 for No 3243; the seven-coordinate metal atom environment here is well distorted from the pentagonal-bipyramidal norm, the largest angle in the coordination sphere being 162.4(1)˚, subtended by Sc–O 2.109(3), 2.128(3) Å, the remaining Sc–O ranging between 2.157(3)–2.219(3) Å.



1992 ◽  
Vol 45 (7) ◽  
pp. 1155 ◽  
Author(s):  
GA Bowmaker ◽  
D Camp ◽  
RD Hart ◽  
PC Healy ◽  
BW Skelton ◽  
...  

The 1 : 1 complexes of the substituted triphenylphosphine ligands mesityldiphenylphosphine and dimesitylphenylphosphine with copper(1) chloride, bromide and iodide have been the subject of single-crystal X-ray structure determinations at 295 K. All six complexes crystallize as air-stable dimeric molecules, [(PPh2Mes)CuX]2 and [ (PPhMes2)CUX]2 with each copper atom in a distorted trigonal PCuX2. coordination environment. Crystals of [(PPh2Mes)CuCl]2 (1) are monoclinic, P21/n, a 9.961(3), b 18.687(6), c 11.009(7) Ǻ, β 114.63(4)°; R was 0.049 for 2450 'observed' reflections. [(PPh2Mes)CuBrI2 (2) is monoclinic, P21/n, a 9.939(2), b 18.832(6), c 11.238(6) Ǻ, β 115.36(3)°; R was 0.046 for 1803 'observed' reflections. [(PPh2Mes)CuI]2.4/3 C6H6 (3) is rhornbohedral, R3, a 36.877(8), c 9.047(5) A; R was 0.039 for 2537 'observed' reflections. Crystals of [(PPhMes2)CuCl]2.2MeCN (4) are triclinic, Pi, a 15.783(7), b 9.570(4), c 8.914(4) Ǻ, α 72.43(3), β 76.37(3), γ 74.03(3)°; R was 0.045 for 3341 'observed' reflections. [(PPhMes2)CuBr]2.3C6H6 (5) is monoclinic, C2/c, a 9.694(6), b 30.15(2), c 20.66(2) Ǻ, β 98.00(7)°; R was 0.047 for 2117 'observed' reflections. [(PPhMes2)CuI]2.2MeCN (6) is orthorhombic, PP1nb, a 11.694(8), b 14.77(1), c 29.76(3) Ǻ; R was 0.049 for 3447 'observed' reflections. Cu-P bond lengths are: 2.196(2) A (1); 2.198(3) Ǻ (2); 2.222(5) and 2.226(5) Ǻ (3); 2.202(1) Ǻ (4); 2.197(3) A (5); 2.201(4) and 2.264(5) Ǻ (6). The geometries of the LCuX2 and CuX2Cu units are compared with data reported for other monomeric and dimeric compounds for both phosphorus- and nitrogen-based ligands L.



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.



1989 ◽  
Vol 42 (2) ◽  
pp. 321
Author(s):  
XY Jia ◽  
JB Bremner ◽  
BW Skelton ◽  
AH White ◽  
KN Winzenberg

The title compounds are 3-aza[6](1,7)-naphthalenophanes with 3-Me and 3-CO2Me substituents, C18H23NO2 and C19H23NO4; in the former the chemical shift of the naphthalene hydrogen enclosed by the medium nitrogen-containing ring is the highest yet observed in a derivative of this type ( σ 9.33). In order to examine the environment of this hydrogen atom and the expected associated naphthalene ring distortions in both compounds, single-crystal X-ray structure determinations have been carried out at 295 K showing the transannular H…N distance in the methyl derivative to be remarkably short at 2.08(2) � . Crystals are triclinic, P1, a 11.683(3), b 10.846(3), c 6.729(2) �, α 90.08(2), β 93.33(2), γ 112.88 Z 2; R was 0.041 for 1378 'observed' reflections. Crystals of the 3-CO2Me derivative are also triclinic, P1, a 12.587(9), b 10.650(4), c 6.758(3) � , a 91.91(3), β 100.51(4), γ 104.74(5)° Z 2; R 0.067 for 1267 'observed' reflections.



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.



1996 ◽  
Vol 49 (10) ◽  
pp. 1135 ◽  
Author(s):  
LM Engelhardt ◽  
JM Harrowfield ◽  
H Miyamae ◽  
JM Patrick ◽  
BW Skelton ◽  
...  

Syntheses and room-temperature single-crystal X-ray structure determinations are recorded for 1:1 adducts of 2,2':6',2"-terpyridine (' tpy ') with the lead(II) oxoanion salts perchlorate, nitrate and nitrite, ( tpy ) Pb ( oxoanion )2. All structures are monoclinic, C2/c, Z = 4, with approximate ranges a from 9 to 11 Ǻ, b from 16 to 20 Ǻ, c from 9.8 to 13.8 Ǻ, β from 113 to 130° and V from 1650 to 1850 Ǻ3. In all cases the lead(II) atoms are disposed on crystallographic 2 axes which also pass through the axis of the central tpy ring; a pair of symmetry related oxoanions link successive lead atoms in a one-dimensional polymeric chain parallel to the ac cell diagonal, one pair of oxygen atoms functioning as an O,O'-bidentate with another oxygen (replaced by the nitrogen in the nitrite) bridging to the adjacent lead atom; the third anionic oxygen atom in the nitrate is replaced by a water molecule in the nitrite, which thus becomes a monohydrate. Residuals were 0.030, 0.034 and 0.040 for 2122, 1564 and 2059 independent 'observed' (I > 3σ(I)) reflections respectively. Also recorded are the syntheses and room-temperature single-crystal X-ray structure determinations for 1:1 aducts of 2,2':6',2"-terpyridine with lead(II) chloride, bromide and iodide, the chloride and bromide being hydrated. ( tpy )PbCl2.H2O is monoclinic, P 21/c, a 8.938(1), b 15,210(7), c 13.414(3) Ǻ, β 115.17(1)°, Z = 4 f.u .; R was 0.036 for No = 3346 independent, 'observed' reflections. The complex is centrosymmetric, binuclear [( tpy ) (H2O)( Cl ) Pb (μ- Cl )2Pb( Cl )(OH2)( tpy )], with the two lead atoms linked by bridging chlorine atoms; the lead atoms are seven-coordinate N3,O,ClPb(μ- Cl )2. The bromide ( tpy )PbBr2.2/3H2O, triclinic, Pī, a 12.360(6), b 12.452(4), c 18.372(6) Ǻ, α 108.31(3), β 109.44(3), γ 90.56(3)°, Z = 6 f.u ., R being 0.046 for No 7282, is in fact trinuclear [Pb3Br6( tpy )6].2H2O, a novel and elegant oligomer with quasi-2 symmetry in which a central lead atom (on the quasi-2 axis) is seven-coordinated [( tpy ) Pb (μ-Br)4] with the associated bromides bridging to a pair of peripheral lead atoms, also seven coordinated, [( tpy )(Br) Pb (μ-Br)3]. Unsolvated ( tpy )PbI2, triclinic, Pī , a 10.834(3), b 9.023(3), c 8.906(2) Ǻ, α 80.34(2), β 89.40(2), γ 79.78(2)°, Z = 2 f.u ., R 0.031 for No 2347 is, like the chloride, centrosymmetric binuclear, [( tpy )(I) Pb (μ-I)2Pb(I)( tpy )], but with the lead(II) now six-coordinate N3(I) Pb (μ-I)2. In both chloride and iodide, the tpy plane is approximately normal to the Pb ... Pb line with the water molecule of the chloride approximately trans to the central tpy nitrogen; in the iodide that site is occupied by the terminal halide.



2015 ◽  
Vol 71 (11) ◽  
pp. 1325-1327 ◽  
Author(s):  
Maxim Bykov ◽  
Elena Bykova ◽  
Vadim Dyadkin ◽  
Dominik Baumann ◽  
Wolfgang Schnick ◽  
...  

Hitherto, phosphorus oxonitride (PON) could not be obtained in the form of single crystals and only powder diffraction experiments were feasible for structure studies. In the present work we have synthesized two polymorphs of phosphorus oxonitride, cristobalite-type (cri-PON) and coesite-type (coe-PON), in the form of single crystals and reinvestigated their crystal structures by means of in house and synchrotron single-crystal X-ray diffraction. The crystal structures ofcri-PON andcoe-PON are built from PO2N2tetrahedral units, each with a statistical distribution of oxygen and nitrogen atoms. The crystal structure of thecoe-PON phase has the space groupC2/cwith seven atomic sites in the asymmetric unit [two P and three (N,O) sites on general positions, one (N,O) site on an inversion centre and one (N,O) site on a twofold rotation axis], while thecri-PON phase possesses tetragonalI-42dsymmetry with two independent atoms in the asymmetric unit [the P atom on a fourfold inversion axis and the (N,O) site on a twofold rotation axis]. In comparison with previous structure determinations from powder data, all atoms were refined with anisotropic displacement parameters, leading to higher precision in terms of bond lengths and angles.



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.



2000 ◽  
Vol 55 (6) ◽  
pp. 487-494 ◽  
Author(s):  
Martin Schwarten ◽  
Michael Witzei ◽  
Dietrich Babel

The results of single crystal X-ray structure determinations are reported for monoclinic (NMe4)2Li(H2O)2[Cr(CN)6] (a = 1736.7(2), = 888.0(1), c = 1659.3(1) p m ,β = 119.33(1)°; C2/c, Z = 4) and orthorhombic (NMe4),Na(H2O)[Cr(CN)6] (a = 960.0(2), b = 885.0(2), c = 1269.8(3) pm; Pnmm, Z = 2) and (NMe4)2Na(H2O)[Co(CN)6] (a = 1854.5(4), b = 853.5(1), c = 1328.7(3) pm; Pnma, Z = 4), the latter exhibiting a superstructure of the NaCr compound. The average distances within the hexacyano groups are Cr-C: 207.8 resp. 208.3 pm and Co-C: 189.5 pm. The alkali ions are incorporated into the elpasolite-like arrangement of the bigger ions as di- or monohydrated species [Li(H2O)2]+ and [Na(H2O)]+ resp., becoming tetrahedrally coordinated [LiO2N2] and [NaON3] within the lattice and fixed by hydrogen bridges O-H...N as well. Some structural details and relations are discussed.



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