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'normal coordinate analysis' in keywords Facet   Publication Year 1991  [X]
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1991[X]
1Author    K. Irmer, W. PreetzRequires cookie*
 Title    Normalkoordinatenanalyse an Oktaederkomplexen des  
 Abstract    Typs [MXW Y6_ J z", M = Ru, Rh, Os, Ir, Pt; X # Y = F, Cl, Br; n = 0 -6 ; z = 1 -3 Normal Coordinate Analysis on Octahedral Complexes of the Type [MX"Y6_ " r , M = Ru, Rh. Os, Ir, Pt; X # Y = F, Cl, Br; n = 0 -6 ; z = 1 -3 Normal coordinate analyses for all com pounds o f the series [MX"Y6_Jr~, M = Ru, Rh. Os, Ir, Pt; X Y = F, Cl, Br; n = 0 -6 ; z = 1 -3 , including the geometric isomers for n = 2, 3, 4 have been performed, based on a general valence force field. For the isostructural species o f the point symmetries Oh (n -0, 6), D 4h (2, 4, trans), C4v (1, 5), C3v (3,fac), C2v (2, 4, cis\ 3, mer) sequences o f decreasing frequencies are established. Due to the different trans influences X < Y (F < Cl < Br) in asymmetric axes X ' -M -Y ' , the M -Y ' bonds are strengthened and the M -X ' bonds are weakened, as indicated by valence force constants for M -Y' up to 21 % high­ er (P t-C l'), for M -X ' down to 18% lower (P t-F '), as compared with the values calculated for symmetrical X -M -X and Y -M -Y axes, respectively. The influence o f the different central ions and their oxidation numbers on the force field is discussed. 
  Reference    Z. Naturforsch. 46b, 1200—1206 (1991); eingegangen am 12. April 1991 
  Published    1991 
  Keywords    Normal Coordinate Analysis, Force Constants, /rans-Influence, Mixed-Ligand Complexes 
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 TEI-XML for    default:Reihe_B/46/ZNB-1991-46b-1200.pdf 
 Identifier    ZNB-1991-46b-1200 
 Volume    46 
2Author    J. Skowronek, W. Preetz, S. M. JessenRequires cookie*
 Title    Darstellung, Schwingungsspektren und Normalkoordinatenanalyse der Acetatochloroditechnetate(III)  
 Abstract    , cis-T ^ C ^ C C F ^ C ^ I^ (L = axiale Donorbase) sowie Kristallstruktur von a s-T c2(0 2CCH3)2Cl4((CH3)2NC0CH3)2 Preparation, Vibrational Spectra and Norm al C oordinate Analysis o f Acetatochloroditechnetates(III), c« -T c2(0 2C CH 3)2C14L2 (L = Axial Donorbase) and the Crystal Structure of ds-Tc2(0 2C CH 3)2Cl4((CFI3)2N C 0C FI3)2 Tc2(0 2C C H 3),C l4(H 20)2 has been prepared by reaction o f [Tc2C18]2" with acetic anhydride and fluoroboric acid. By treatment with the donor bases L = N ,N-dim ethylform am ide (D M F), N ,N-dim ethylacetam ide (D M A A), dimethylsulfoxide (D M SO), triphenylphosphin-oxide (TPO) and pyridine (Py), the green adducts Tc2(0 2CCH3)2Cl4L2 are formed. The structure o f T c,(O .C C H 3),C l4(D M A A), was determined by X-ray diffraction; space group C 2/c with a = 29.604(4), b = 10.895(2), c = 14.404(2) Ä, ß = 97.87(2)°, Z = 8, /?w = 2.7% . The T c -T c distance is 2.1835(7) Ä , the bridging acetate groups are in c/s-positions. The IR and Raman spectra have been recorded at 80 K and assigned according to point group C-,v, supported by a normal coordinate analysis o f Tc2(0 2C C H 3)2C14(D M A A)2 based on a general valence force field. The stretching interaction constant fd(TcTc) is determined to 3.38 m dyn/Ä. With in­ creasing donor strength o f the axial ligands, the intense Raman vibration v(TcTc), showing up to three overtones, is lowered from 311 to 282 cm *1. The <5-<5* transitions o f all adducts are observed at 6 4 8 -6 5 2 nm. 
  Reference    Z. Naturforsch. 46b, 1305—1314 (1991); eingegangen am 4. März 1991 
  Published    1991 
  Keywords    Diacetatotetrachloroditechnetate(III) Adducts, Synthesis, Crystal Structure, Vibrational Spectra, Normal Coordinate Analysis 
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 TEI-XML for    default:Reihe_B/46/ZNB-1991-46b-1305.pdf 
 Identifier    ZNB-1991-46b-1305 
 Volume    46 
3Author    J. Thesing, J. Baurmeister, W. Preetz, D. Thiery, H. G. Von SchneringRequires cookie*
 Title    Kristallstrukturen  
 Abstract    von [P(C6H 5)4 l2 lB6Cl6](CH3CN) 2 und |P(C 6H 5)4]2 lB6Br6](CH3CN) 2 sowie Schwingungsspektren und Normalkoordinatenanalyse der isotopomeren c/osö-Hexahalogenohexaborate |"B",#B6-Ä I 2' , X = Cl, Br; n = 0 -6 Crystal Structures o f [P(C6H 5)4]2[B6C16](C H ,C N)2 and [P(C6H s)4]2[B6Br6](CH3CN)2, Vibrational Spectra and Norm al C oordinate Analysis of Isotopomeric cVavo-Hexahalogenohexaborates [n B"10B6_/?X6]2", X = Cl, Br; n = 0 -6 The crystal structures o f (TPP)2[B6C16](CH3CN)2 and (TPP)2[B6Br6](CH3CN)2 were deter­ mined from single crystal X-ray diffraction analyses at 147 K. They are triclinic, space group P I, and contain nearly regular octahedral anions with bond lengths d (B -B) 1.716, d (B -C l) 1.818 for [B6C16]2" and d (B -B) 1.684, d (B -B r) 1.993 A for [B6Br6]2~. Using these molecular data, norm al coordinate analyses for the ten isotopomers [n Bnl0B6_nX6]2", n = 0 -6 , X = Cl, Br, including the pairs of geometric isomers for n = 2, 3, 4 have been performed, based on a general valence force field. W ith a set of 8 force constants for Cs2[B6Br6] (e.g. fd(BB) = 1.39, fd(BBr) = 3.18 mdyn/Ä) and 10 for Cs2[B6Cl6] (e.g. fd(BB) = 1.30, fd(BCl) = 4.01 mdyn/Ä) the calculated frequencies are in good agreement with observed IR (10 K) and Raman bands (80 K) in natural abundance as well as for "B-and l0B-enriched derivatives. For the series [B6X6]2", X = Cl, Br, I the correlation of decreasing bond lengths d(B -B) and increasing force constants fd(BB) along with vibrational coupling between the B6 cage and the substituent sphere is discussed. 
  Reference    Z. Naturforsch. 46b, 800—808 (1991); eingegangen am 6. Dezember 1990 
  Published    1991 
  Keywords    H exachlorohexaborate(2-), H exabrom ohexaborate(2-), Crystal Structure, Normal Coordinate Analysis, Isotopomers 
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 TEI-XML for    default:Reihe_B/46/ZNB-1991-46b-0800.pdf 
 Identifier    ZNB-1991-46b-0800 
 Volume    46