Kristallstruktur, Schwingungsspektren und Normalkoordinatenanalyse von trans-(Et4N)[OsF4Cl2] / Crystal Structure, Vibrational Spectra and Normal Coordinate Analysis of trans-(Et4N)[OsF4Cl2]

2000 ◽  
Vol 55 (8) ◽  
pp. 691-694 ◽  
Author(s):  
B. Lorenzen ◽  
W. Preetz

Abstract By careful oxidation of trans-tetrafluorodichloroosmate(IV) with PbO2/trifluoroacetic acid in dichloromethane the corresponding osmium(V) complex anion rran5 -[OsF4Cl2]- is for­ med. The X-ray structure determination on a single crystal has been performed of trans-(Et4N)[OsF4Cl2] (triclinic, space group P1̄a = 7.190(5), b = 7.205(5), c = 7.732(5) Å, a = 71.28(1), β = 71.32(1), 7 = 70.76(1)°, Z = 1). Based on the molecular parameters of the X-ray determination the IR and Raman spectra of the complex have been assigned by normal coordi­ nate analysis. The valence force constants are: fd(OsCl) = 2.13 and fd(OsF) = 3.81 mdyn/Å.

1998 ◽  
Vol 53 (1) ◽  
pp. 13-16
Author(s):  
J. Seemann ◽  
W. Preetz

By treatment of [PtCl6]2- with an excess of SCN– in aqueous solution [Pt(SCN)6]2- is formed. The X-ray structure determination on a single crystal of [Py2CH2][Pt(SCN)6] (orthor-hombic, space group Pna21, a = 15.5084(9), b = 11.8444(11), c = 13.2830(9)Å, Z = 4) shows, that the thiocyanate groups are exclusively S-coordinated with average Pt-S distances of 2.378 Å and Pt-S-C angles in the range from 103.1° to 108.1°. Based on the molecular parameters of the X-ray determination the low temperature (10 K) IR and Raman spectra have been assigned by normal coordinate analysis. The valence force constant is fd(PtS) = 1.62 mdyn/Å.


1999 ◽  
Vol 54 (9) ◽  
pp. 1109-1115
Author(s):  
A. Strueß ◽  
W. Preetz

The crystal structure of trans-(Ph3PNPPh3)2[OsO2(CN)2(OCH3)]2 (triclinic, space group P1̄, a = 11.816(2), b = 13.480(3), c = 13.610(5) Å, α = 83.46(2), ß = 77.09(2), γ = 71.06(2)°, Z = 1) has been determined by single crystal X-ray diffraction analysis. The IR and Raman spectra of the (n-Bu4N)-salts of trans-[OsO2(CN)4]2- (1), trans-[OsO2(CN)2(OH)]22- (2) and trans-[OsO2(CN)2(OCH3)]22- (3) were measured at room temperature. Based on the molecular parameters of the X-ray determination normal coordinate analyses have been performed and the vibrations are assigned. The valence force constants of 1 are fd(Os=O) = 6.5, fd(Os-C) = 2.62 and fd(C≡N ) = 16.85 mdyn/A, of 2 and 3 are fd(Os=O) = 6.7, fd(Os-C) = 2.55 and fd(C≡N ) = 16.95 mdyn/Å. fd(Os-O) ranges from 2.0 - 2.2 and for the methoxy bridge is fd(C-O) = 4.00 mdyn/Å


2002 ◽  
Vol 57 (9) ◽  
pp. 1036-1042 ◽  
Author(s):  
J.-G. Uttecht ◽  
C. Nöther ◽  
W. Preetz

On exposure of trans-(n-Bu4N)2[Pt(SCN)2(ox)2] to photochemical reduction (n-Bu4N)2- [Pt(SCN)2(ox)] (1) is formed. Further treatment with (SCN)2 yields (n-Bu4N)2- [Pt(SCN)4(ox)] (2). The X-ray structure determination on a single crystal was performed of [(C5H5N)2CH2][Pt(SCN)4 (ox)] (triclinic, space group P1̅, a = 9.823(1), b = 14.850(1), c = 15.799(1) Å , α= 74.304(9), β= 86.268(9), γ= 87.455(9)°, Z = 4). Based on the molecular parameters of the X-ray determination the IR and Raman spectra have been assigned by normal coordinate analysis. The valence force constants of the symmetric axis S-Pt-S and of the asymmetrically coordinated S'-Pt-O* axes are fd(PtS) = 1.71, fd(PtS') = 1.92 (1), fd(PtS') = 2.02 (2) and fd(PtO•) = 2.45 (1) and 2.24 (2) mdyn/Å. Taking into account increments of the trans influence a good agreement between observed and calculated frequencies is achieved. The NMR shifts are δ(195Pt) = 1967.7 (1) and 2930.8 ppm (2)


1998 ◽  
Vol 53 (11) ◽  
pp. 1338-1342 ◽  
Author(s):  
A. Strueß ◽  
W. Preetz

The treatment of K2[OsO2(OH)4] with oxamide in aqueous solution yields [OsO2(N2H2C2O2)2]2-. The crystal structure of trans-(Ph4P)2[ OsO2(N2H2C2O2)2]·CH2Cl2 (triclinic, space group P1̅, a = 10.447(1), b = 14.102(4), c = 16.962(2) Å, a = 90.037(1), β = 90.633(7), γ = 98.812(2)°, Z = 2) has been determined by single crystal X-ray diffraction analysis. The IR and Raman spectra were measured at room temperature. Based on the molecular parameters of the X-ray determination a normal coordinate analysis has been performed and the vibrations are assigned. The valence force constants are fd(Os=O) = 6.7, fd(Os-N) = 2.4, fd(C-N) = 4.9, fd(C=0) = 11.15 and fd(C-C) = 4.7 mdyn/Å.


2008 ◽  
Vol 63 (5) ◽  
pp. 530-536 ◽  
Author(s):  
Olaf Reckeweg ◽  
Francis J. DiSalvo

Single crystals of Ca11N6[CN2]2 (dark red needles, tetragonal, P42/mnm (no. 136), a = 1456.22(5), and c = 361.86(2) pm, Z = 2), Ca4N2[CN2] (transparent yellow needles, orthorhombic, Pnma (no. 62), a = 1146.51(11), b = 358.33(4), and c = 1385.77(13) pm, Z = 4) and Ca[CN2] (transparent, colorless, triangular plates, rhombohedral, R3̅m (no. 166), a = 369.00(3), and c = 1477.5(3) pm, Z = 3) were obtained by the reaction of Na2[CN2], CaCl2 and Ca3N2 (if demanded by stoichiometry) in arc-welded Ta ampoules at temperatures between 1200 - 1400 K. Their crystal structures were re-determined by means of single crystal X-ray structure analyses. Additionally, the Raman spectra were recorded on these same single crystals, whereas the IR spectra were obtained with the KBr pellet technique. The title compounds exhibit characteristic features for carbodiimide units with D∞h symmetry (d(C-N) = 121.7 - 123.8 pm and ∡ (N-C-N) = 180°). The vibrational frequencies of these units are in the expected range (Ca11N6[CN2]2: νs = 1230, νs = 2008; δ = 673/645/624 cm−1; Ca4N2[CN2]: νs = 1230, νs = 1986; δ = 672/647 cm−1; Ca[CN2]: νs = 1274, νs = 2031, δ = 668 cm−1). The structural results are more precise than the previously reported data, and with the newly attained Raman spectrum of Ca11N6[CN2]2 we correct data reported earlier.


1992 ◽  
Vol 47 (12) ◽  
pp. 1687-1692 ◽  
Author(s):  
Heinz Dieter Lutz ◽  
Peter Kuske ◽  
Arno Pfitzner ◽  
Hermann-Josef Steiner

The crystal structure of the novel pink Li5CrCl8 oC28 has been determined by both single crystal X-ray and neutron powder studies. The title compound crystallizes in a hitherto unknown structure type (space group C mmm, Z = 2). The final R values are R = 3.4% (715 independent reflections with I > 3aI) and Rwp = 11.5%, respectively (a = 1019.79(3), b = 723.94(2) and c = 726.16(3) pm). The structure consists of edge-connected Li(l)Cl6 and alternating edge-connected Li(2)Cl6 and CrCl6 octahedra, respectively. It is related to the NaCl super structure SnMn2S4 type. IR and Raman spectra as well as symmetry coordinates are given and discussed in terms of CrCl6 and LiCl6 breathing modes.


1999 ◽  
Vol 54 (6) ◽  
pp. 772-776 ◽  
Author(s):  
C. Drewes ◽  
W. Preetz

By electrochemical oxidation of (n-Bu4N)[B6H5Hfac(C2H5)] in the presence of nitrite ions and of the base DBU in dichloromethane solution cis-[B6H4(C2H5)(NO2)]2- is formed. X-ray diffraction analysis has been performed on a single crystal of cis-(Ph4 As)2[B6H4(C2H5)(NO2)] (triclinic, space group P1; a = 10.673(4). b = 10.907(4), c = 21.237(4) A, α = 80.789(4), β = 83.117(4), γ = 66.548(2)°, Z = 2). The 11B NMR spectrum is consistent with a disubstituted octahedral B6 cage with local Cs symmetry. The IR and Raman spectra exhibit characteristic CH3, CH2, NO2, BN, BH and B6 vibrations


1994 ◽  
Vol 47 (5) ◽  
pp. 829 ◽  
Author(s):  
TW Hambley ◽  
TW Hambley ◽  
GA Lawrance ◽  
GA Lawrance ◽  
M Maeder ◽  
...  

The branched, potentially quinquedentate , 5-methyl-3,7-diazanonane-1,5,9-triamine (1) reacts in hot water with rhodium(III) chloride to yield fac -[ Rh (H2(1))Cl3]2+. Only upon extended reflux for several weeks is coordination as a quinquedentate achieved. The fac complex was crystallized readily as a mixed chloride perchlorate trihydrate salt, in the triclinic space group Pī , a 8.666(2), b 10.319(2), c 12.558(3) Ǻ, α 94.34(2), β 98.86(2), γ 97.75(2)°, Z = 2; a single-crystal X-ray structure determination was refined to Rw 0.037 for 3703 'observed' reflections. The central primary amine and two adjacent secondary amines occupy an octahedral face, with the chloro ligands then necessarily fac also. The Rh -N distances vary, with the shortest distance to the primary amine [2.023(2)Ǻ] rather than to the secondary amines [2.066(2), 2.077(2) Ǻ], as do the Rh-Cl distances [range 2.345(1)-2.369(1)Ǻ]. The two primary amines on the chain terminals remain uncoordinated, the central facially capping unit preferring coordination first, possibly indicating a general intermediate for coordination of polydentate l igands containing this type of unit.


1998 ◽  
Vol 53 (8) ◽  
pp. 823-828 ◽  
Author(s):  
A. Strueß ◽  
W. Preetz

Abstract The crystal structures of trans-(Ph4P)2[OsO2(ox)2] (monoclinic, space group P21/n, a = 12.281(2), b = 14.5440(13), c = 13.9810(12) Å, β = 100.000(8)°, Z = 2) and trans- (n-Bu4N)2[OsO2(mal)2] (triclinic, space group P1̄, a = 10.365(4),b = 10.707(3), c - 11.473(5) A, a = 73.00(2), β = 64.44(3), 7 = 82.55(3)°, Z = 1) have been determined by single crystal X-ray diffraction analysis. The IR and Raman spectra of these complexes were measured at room temperature. Based on the molecular parameters of the X-ray determinations normal coordinate analyses have been performed and the vibrations assigned. The valence force constants of [OsO2(ox)2]2- are fd(Os=O) = 6.7, fd(Os-O) = 2.9, fd(C-O) = 5.05, fd(C=O) = 11.2 and fd(C-C) = 4.7 mdyn/Å and of [OsO2(mal)2]2- fd(Os=O) = 6.7, fd(Os-O) = 2.9, fd(C-O) = 4.86, fd(C=O) =11.1 and fd(C-C) = 4.07 mdyn/Å.


2000 ◽  
Vol 55 (2) ◽  
pp. 178-184 ◽  
Author(s):  
L. Homolya ◽  
W. Preetz

The crystal structures of cis-(n-Bu4N)2[ReBr4(NCS)2] (1) (triclinic, space group P1̄, a = 11.475(6), b = 20.096(16), c = 22.144(11) Å, α = 110.56(6), β = 92.97(5), γ = 99.77(7)°, Z = 4), cis-(n-Bu4N)2[ReBr4(NCS)2] (2) (triclinic, space group P1̄, a = 11.527(3), b = 20.237(7), c = 22.07(2) Å, α = 110.05(4), β = 93.86(6), γ = 99.49(4)°, Z = 4) and cis-{n- Bu4N)2[ReBr4(NCS)(NCSe)] (3) (triclinic, space group P1̄, a = 11.488(2), b = 20.164(6), c = 22.158(5) Å, α = 110.44(2), β = 93.34(2), γ = 99.626(18)°. Z = 4) have been determined by single crystal X-ray diffraction analysis. Based on these molecular parameters the low temperature (10 K) IR and Raman spectra of the (n-Bu4N) salts have been assigned by normal coordinate analysis. The valence force constants are fd(ReN) = 1.70 (1), 1.70 (2) and 1.72 (3), fd(ReBr) = 1.36 (1), 1.30 (2) and 1.36 mdyn/Å (3).


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