Darstellung, Kristallstruktur, Schwingungsspektren und Normalkoordinatenanalyse von trans-[OsO2(N2H2C2O2)2]2- / Synthesis, Crystal Structure, Vibrational Spectra, and Normal Coordinate Analysis of trans-[OsO2(N2H2C202)2]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.

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


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.


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.


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. 1329-1334 ◽  
Author(s):  
L. Homolya ◽  
S. Strueß ◽  
W. Preetz

The crystal structures of cis-(n-Bu4N)2[ReCl4(NCS)2] (triclinic, space group P1̅, a = 11,245( 1), b = 20.174(3), c = 21.320(8) Å, a =109.06(2), β = 96.46(2), γ = 98.22(5)°, Z = 4) and cis-(Ph4P)2[ReCl4(NCSe)2]·2CH2Cl2 (triclinic, space group P1̅, a = 10.341(2), b = 13.436(3), c = 19.616(4) Å, α = 92.70(2), β = 92.02(2), γ = 89.99( 1)°, Z= 2) have been determined by single crystal X-ray diffraction analysis. Both ambidentate ligands NCS and NCSe are bonded via the N atom. Using the molecular parameters of the X-ray determinations the low temperature (10 K) IR and Raman spectra of the (n-Bu4N) salts have been assigned by normal coordinate analysis based on a modified valence force field. The valence force constants fd(ReN) are 1,78(NCS) and 1,79(NCSe) mdyn/ Å.


1996 ◽  
Vol 51 (4) ◽  
pp. 551-556 ◽  
Author(s):  
W. Preetz ◽  
B. Steuer

Abstract By reaction of [B6H6]2- with a solution of (SCN)2 in dichloromethane in the presence of solid KOH the hexaisothiocyanatodiborate anion [B2(NCS)6]2- is formed and can be isolated by fractionated crystallization. The crystal structure of (PNP)2[B2(NCS)6] has been determined by single crystal X-ray diffraction analysis; triclinic space group P1̄ with a=12,282(5), b=12,416(5), c=14,155(5)Å, a=68,36(5), β=70,59(5), γ=80,93(5)°.The [B2(NCS)6]2- anion reveals a staggered conformation with nearly local D3d symmetry and a B-B bond length of 1,73(2) Å. Using the crystallographic data a normal coordinate analysis has been performed. With a set of 12 force constants (e.g. fd(BB)=3,62, fd(BN)=4,21 mdyn/Å) a good agreement between observed and calculated frequencies for the 10B and 11B isotopomers has been achieved. The potential energy distribution on the force constants reveals strong vibrational couplings within the B2N6 framework.


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


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.


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).


1999 ◽  
Vol 54 (9) ◽  
pp. 1116-1121
Author(s):  
A. Strueß ◽  
W. Preetz

By careful acidification of the aqueous solution of trans-K2[OsO2(OH)4] in the presence of the required amount of cyanide ions with oxalic acid, malonic acid or oxamide the osmyl complexes trans-[OsO2(CN)2(ox)]2- (1), trans-[OsO2(CN)2(mal)]2- (2) und trans-[OsO2(CN)2(N2H2C2O2)]2- (3) are formed. The IR and Raman spectra of the (n-Bu4N) and (Et4N) salts of 1, 2 und 3 were measured at room temperature. Based on the molecular parameters of the X-ray determination of related complexes normal coordinate analyses have been performed and the vibrations were assigned. The valence force constants are fd(C≡N ) = 16.95, fd(Os=O) = 6.68 - 6.70, fd(Os-O) = 2.55 - 2.60, fd(Os-C) = 2.55 and fd(Os-N) = 2.30 mdyn/Å. For the chelate ligands, fd(C =0) ranges from 11.03 - 11.15, fd(C-O/N) from 4.86 - 5.05 and fd(C-C) from 4.07 - 4.70 mdyn/Å.


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