Darstellung,Schwingungsspektren, Normalkoordinatenanalyse und Kristallstruktur von fac-(PPN)2[ReClBr2I3]

Preparation, Vibrational Spectra, Normal Coordinate Analysis, and Crystal Structure of fac-(PPN)₂[ReClBr₂I₃] By treatment of cis-[ReBr₂I₄]^2? with HCl fac-[ReClBr₂I₃]^2? is formed beside other mixed complex ions of the Type [ReCl_kBr_lI_m]^2?, k + l + m = 6, which have been separated by ion exchange chromatography on diethylaminoethyl cellulose. The X-ray structure determination on single crystals of (PPN)₂[ReClBr₂I₃] (monoclinic, space group P2₁/c, a = 22.059(3), b = 13.569(2), c = 23.9679(2) Å, β = 106.194(4)°, Z = 4) reveals the complete ordering of the complex anions. Due to the different trans influence the bond lengths ReCl (2.39) and ReBr (2.50) are slightly increased, the average ReI distance (2.66 Å) is a little shortened as compared with corresponding homoleptic octahedral complexes. The well resolved low temperature (80 K) IR and Raman spectra exhibit rheniumhalogen stretching vibrations in characteristic regions. The assignment is confirmed by the normal coordinate analysis based on a general valence force field. Taking into account increments of the trans influence on the valence force constants of the structural groups an adjustment between calculated and observed frequencies within a few cm^?1 is achieved.     

Kristallstruktur,Schwingungsspektren und Normalkoordinatenanalyse von K2[IrCl5(NH3)]

Crystal Structure, Vibrational Spectra, and Normal Coordinate Analysis of K₂[IrCl₅(NH₃)] The X-ray structure determination of K₂[IrCl₅(NH₃)] (orthorhombic, space group Pnma, a = 13.426(4), b = 10.015(2), c = 6.8717(7) Å, Z = 4) revealed the C_s point symmetry of the complex anion [IrCl₅(NH₃)]^2? (Ir? Cl = 2.337–2.365, Ir? N = 2.067(10); N? H = 0.73–0.79 Å). Using the molecular parameters the IR and Raman spectra are assigned by normal coordinate analysis. The valence force constants are f_d(NH) = 5.88, f_d(IrN) = 2.66, f_d(IrCl) = 1.68 mdyn/Å.     

Darstellung,Kristallstruktur, Schwingungsspektren und Normalkoordinatenanalyse von K2[OsCl5(CO)] · H2O

Synthesis, Crystal Structure, Vibrational Spectra, and Normal Coordinate Analysis of K₂[OsCl₅(CO)] · H₂O The X-ray structure determination of K₂[OsCl₅(CO)] · H₂O (monoclinic, space group P2₁/c a = 13.600(2), b = 7.122(1), c = 22.186(11) Å, β = 98.66(3)°, Z = 8) revealed two crystallographic independent bat very similar complex anions [OsCl₅(CO)]^2? with rough C_4v point symmetry. Due to the stronger trans influence of the carbonyl group the bond lengths in the Cl? Os? CO axis Os? Cl = 2.449(2), 2.430(2) Å are langer as compared with the octahedron basis Os? Cl = 2.340-2.370 Å. The water of crystallization is coordinated to potassium (K? OH₂ = 2.625-2.815 Å). Using the molecular parameters the IR and Raman spectra are assigned by normal coordinate analysis. The valence force constants are f_d(CO) = 15.30, f_d(OsC) = 3.88, f_d(OsCl) = 1.81, f_d(OsCl) = 1.36, f_d(OH) = 7.65, 7.82, 7.79 mdyn/Å. The strengthening of the Os? C bond by stronger back donation of the Os^III(d⁵) complex in comparison with the isostructural Os^IV (d⁴) compound is discussed.     

Kristallstrukturen,Schwingungsspektren und Normalkoordinatenanalyse von cis-(Et4N)[OsF2Cl4] und trans-(Ph4P)[OsF2Cl4]

Crystal Structures, Vibrational Spectra, and Normal Coordinate Analysis of cis -(Et₄N)[OsF₂Cl₄] and trans -(Ph₄P)[OsF₂Cl₄] By oxidation of the pure fluorochloroosmates(IV) with KBrF₄ or PbO₂/trifluoracetic acid in dichloromethane the mixed pentavalent complex anions cis-[OsF₂Cl₄]^– and trans-[OsF₂Cl₄]^– are formed. X-ray structure determinations on single crystals have been performed of cis-(Et₄N) · [OsF₂Cl₄] ( 1 ) (monoclinic, space group P2₁/n, a = 7.519(2), b = 17.648(2), c = 11.942(4) Å, β = 105.98(2)°, Z = 4) and trans-(Ph₄P)[OsF₂Cl₄] ( 2 ) (tetragonal, space group P4/n, a = 12.677(2), c = 7.743(1) Å, Z = 2). Based on the molecular parameters of the X-ray determinations and assuming C_2v point symmetry for the anion of 1 and D_4h point symmetry for the anion of 2 the IR and Raman spectra have been assigned by normal coordinate analysis. Due to the stronger trans influence of chlorine as compared with fluorine for F ^· –Os–Cl′ axes significally different valence force constants are observed in comparison with symmetrically coordinated axes: f_d(OsF ^· ) = 3.35, f_d(OsF) = 3.73, f_d(OsCl′) = 2.05 and f_d(OsCl) with 1.98 and 2.00 mdyn/Å.     

Darstellung und Kristallstruktur von trans-(Ph4As)2[OsCl2(NCS)(SCN)], Schwingungsspektren und Normalkoordinatenanalyse

Preparation and Crystal Structure of trans-(Ph₄As)₂[OsCl₂(NCS) (SCN) ], Vibrational Spectra and Normal Coordinate Analysis By treatment of trans-[OsCl₂I₄]^2? with (SCN)₂ in dichloromethane a mixture of different linkage isomers is formed, from which trans-[OsCl₂(NCS)(SCN)]^2? has been isolated by ion exchange chromatography on diethylaminoethyl cellulose. The X-Ray structure determination on a single crystal of trans-(Ph₄As)₂[OsCl₂(NCS)(SCN)] (triclinic, space group P 1 , a = 12.505(5), b = 12.056(5), c = 19.833(5) Å, α = 108.047(5)°, β = 91.964(5)°, γ = 117.048(5)°, Z = 2) reveals that two cis-positioned Thiocyanate(N) groups are coordinated with Os? N? C angles of 172.1° and 173.0° and two cis-positioned Thiocyanate(S) groups are coordinated with Os? S? C angles of 106.9° and 108.7°. Using the molecular parameters of the X-Ray determination the low temperature (10 K) IR and Raman spectra of the (n-Bu₄N) salt of the linkage isomer are assigned by a normal coordinate analysis based on a modified valence force field. The valence force constants are f_d(OsN) = 1.63 and f_d(OsS) = 1.30 mdyn/Å. Taking into account the trans influence a good agreement between observed and calculated frequencies is achieved.     

Kristallstruktur von (Me4N)3[Ir(SCN)6], Schwingungsspektrum und Normalkoordinatenanalyse

Crystal Structure of (Me₄N)₃[Ir(SCN)₆], Vibrational Spectra and Normal Coordinate Analysis From a mixture of the linkage isomers [Ir(NCS)_n(SCN)_6–n]^3–, n = 0–2, pure [Ir(SCN)₆]^3– has been isolated by ion exchange chromatography on diethylaminoethyl cellulose. The X-ray structure determination on a single crystal of (Me₄N)₃[Ir(SCN)₆] (trigonal, space group R3, a = 14.838(2), c = 23.827(1) Å, Z = 6) reveals the presence of two crystallographically independent complex anions which C_3i symmetry correlates with the cation/anion ratio 3 : 1. The thiocyanate ligands are exclusively S-coordinated with the average Ir–S distance of 2.384 Å and the Ir–S–C angle of 106.4°. The torsion angles S–Ir–S–C are 17.5 and 42.1°. The IR and Raman spectra of the (n-Bu₄N) salt are assigned by normal coordinate analysis based on the molecular parameters of the X-ray determination. The valence force constant f_d(IrS) is 1.57 mdyn/Å.     

Darstellung und Kristallstruktur von Tetraphenylphosphonium-Hexathiocyanatorhodat(III), [P(C6H5)4]3[Rh(SCN)6]

Preparation and Crystal Structure of Tetraphenylphosphonium Hexathiocyanatorhodate(III), [P(C₆H₅)₄]₃[Rh(SCN)₆] By treatment of RhCl₃ · n H₂O with KSCN in water a mixture of the linkage isomers [Rh(NCS)_n(SCN)_6–n]^3?, n = 0–2 is formed which is separated by ion exchange chromatography on diethylaminoethyl cellulose. The X-ray structure determination on a single crystal of [P(C₆H₅)₄]₃[Rh(SCN)₆] (monoclinic, space group C1c1, a = 13.620(5), b = 22.929(13), c = 22.899(9) Å, β = 98.55(3)°, Z = 4) confirms the coordination of all ligands via S with the middle Rh? S distance of 2.372 Å and Rh? S? C angles of 109°. The SCN groups are nearly linear with 175° and averaged bondlengths S? C 1.63 and C? N 1.14 Å. The crystal lattice is build up by layers of complex anions and voluminous cations with no specific interactions but which are closely connected by thiocyanate ligands and phenyl rings.     

Darstellung,Kristallstruktur und Normalkoordinatenanalyse der bindungsisomeren Pentachlororhodanoosmate(IV)

Preparation, Crystal Structure and Normal Coordinate Analysis of Linkage Isomeric Pentachlororhodanoosmates(IV) By treatment of [OsCl₅I]^2? with (SCN)₂ in dichloromethane the linkage isomers [OsCl₅(NCS)]^2? and [OsCl₅(SCN)]^2? are formed which have been separated by ion exchange chromatography on diethylaminoethyl cellulose. The X-ray structure determination on single crystals of (Ph₄As)₂[OsCl₅(NCS)] (monoclinic, space group P2₁/a, a = 18.872(2), b = 11.6024(2), c = 22.786(1), β = 109.057(1)°, Z = 4) and (Ph₄As)₂[OsCl₅(SCN)] (monoclinic, space group P2₁/a, a = 19.057(2), b = 11.306(2), c = 22.612(1), β = 106.64(2)°, Z = 4) reveals the complete ordering of the complex anions. The thiocyanate group is located above one of the Cl ligands of the equatorial plane with the Os? N? C angle of 166.1° for N bonding and the Os? S? C angle of 109.9° for S bonding. The IR and Raman spectra of both linkage isomers known from literature are assigned by normal coordinate analysis based on the general valence force field using the molecular parameters of the X-ray determination. The valence force constants are f_d(OsN) = 1,81 and f_d(OsS) = 1,32 mdyn/Å. Taking into account increments of the trans influence a good adjustment between observed and calculated frequencies is achieved.     

Darstellung,Schwingungsspektren und Normalkoordinatenanalyse von mer-[OsCl3I(NCS)]2− sowie Kristallstrukturanalyse von zwei Modifikationen des mer-(Ph4As)2[OsCl3I(NCS)2c]

Preparation, Vibrational Spectra, and Normal Cooordinate Analysis of mer-[OsCl₃I(NCS)₂^c]^2? and Crystal Structures of two Modifications of mer-(Ph₄As)₂[OsCl₃I(NCS)₂^c] By treatment of cis-/trans-[OsCl₄I₂]^2? or fac-[OsCl₃I₃]^2? with (SCN)₂ in dichloromethane mixtures of different linkage isomers are formed, from which mer-[OsCl₃I(NCS)]^2? has been isolated by ion exchange chromatography on diethylaminoethyl cellulose. With tetraphenylarsonium ions mer-(Ph₄As)₂[OsCl₃I(NCS)₂^c] crystallizes in two different modifications. From acetone solution the high-temperature form α precipitates above ?10°C, the low-temperature form β below, ?65°C. The X-Ray structure determinations on single crystals of α-mer-(Ph₄As)₂[OsCl₃I(NCS)₂^c] (triclinic, space group P 1 , a = 10.245(5), b = 11.690(5), c = 22.027(5) Å, α = 83.650(5)°, β = 85.734(5)°, γ = 72.566(5)°, Z = 2) and β-mer-(Ph₄As)₂[OsCl₃I(NCS)₂^c] (triclinic, space group P 1 , a = 10.959(5), b = 11.122(5), c = 21.745(5) Å, α = 97.677(5)°, β = 92.339(5)°, γ = 104.712(5)°, Z = 2) reveal the ordering of the complex anions, which significantly differ in their geometry. The via N coordinated thiocyanate groups exhibit Os? N? C angles of 172.7° and 173.3° (α) and of 164.4° and 175.4° (β). Using the molecular parameters of the X-Ray determinations the low temperature (10 K) IR and Raman spectra of the (n-Bu₄N) salt of the complex anion are assigned by a normal coordinate analysis based on a modified valence force field. The valence force constants are f_d(OsN) = 1.66 and 1.64 mdyn/Å. Taking into account the trans influence a good agreement between observed and calculated frequencies is achieved.     

Darstellung,Kristallstrukturen, Schwingungsspektren und Normalkoordinatenanalysen von trans-(PNP)[TcCl4(Py)2] und trans-(PNP)[TcBr4(Py)2]

Preparation, Crystal Structures, Vibrational Spectra, and Normal Coordinate Analysis of trans-(PNP)[TcCl₄(Py)₂] and trans-(PNP)[TcBr₄(Py)₂] By reaction of (PNP)₂[TcX₆] with pyridine in the presence of [BH₄]^? (PNP)[TcX₄(Py)₂], X = Cl, Br, are formed. X-ray structure determinations on single crystals of these isotypic Tc^III complexes (monoclinic, space group P2₁/n, Z = 2, for X = Cl: a = 13.676(4), b = 9.102(3), c = 17.144(2) Å, β = 91.159(1)°; for X = Br: a = 13.972(2), b = 9.146(3), c = 17.285(4) Å, β = 90.789(2)°) result in the averaged bond distances Tc? Cl: 2.386, Tc? Br: 2.519, Tc? N: 2.132(3) (X = Cl) and 2.143(4) Å (X = Br). The two pyridine rings are coplanar and vertical to the X? Tc? X-axes, forming angles of 42.28° (X = Cl) and 43.11° (X = Br). Using the molecular parameters of the X-ray structure determination and assuming D_2h point symmetry, the IR and Raman spectra are assigned by normal coordinate analysis based on a modified valence force field. Good agreement between observed and calculated frequencies is obtained with the valence force constants f_d(TcCl) = 1.45, f_d(TcBr) = 1.035, f_d(TcN) = 1.37 (X = Cl) and 1.45 mdyn/ Å (X = Br), respectively.     

Darstellung,spektroskopische Charakterisierung und Kristallstrukturen von [(C5H5N)2CH2][PtCl5(SCN)] und cis-[(C5H5N)2CH2][PtCl4(SCN)2]

Preparation, Spectroscopic Characterization, and Crystal Structures of [(C₅H₅N)₂CH₂][PtCl₅(SCN)] and cis -[(C₅H₅N)₂CH₂][PtCl₄(SCN)₂] By treatment of [PtCl₆]^2– with SCN^– in aqueous solution a mixture of chlorothiocyanatoplatinates(IV) is formed, from which [PtCl₅(SCN)]^2– and cis-[PtCl₄(SCN)₂]^2– have been separated by ion exchange chromatography on diethylaminoethyl cellulose. X-Ray structure determinations on single crystals of [(C₅H₅N)₂CH₂][PtCl₅(SCN)] ( 1 ) (tetragonal, space group P 4₃, a = 7.687(1), c = 29.698(4), Z = 4) and cis-[(C₅H₅N)₂CH₂][PtCl₄(SCN)₂] ( 2 ) (monoclinic, space group P 2₁/n, a = 11.2467(9), b = 15.0445(10), c = 11.3179(13), β = 92.840(9)°, Z = 4) show, that the thiocyanate groups are coordinated via S atoms with average Pt–S distances of 2.339 Å and Pt–S–C angles of 104.7° up to 107.1°. Using the molecular parameters of the X-ray determinations the low temperature (10 K) IR and Raman spectra have been assigned by normal coordinate analyses. The valence force constants of the S–Pt–Cl˙ axes are f_d(PtS) = 1.81 ( 1 ) and 1.87 ( 2 ), f_d(PtCl ^× ) = 1.77 ( 1 ) and 1.81 ( 2 ), of the Cl–Pt–Cl axes are f_d(PtCl) = 1.93 ( 1 ) and 1.90 mdyn/Å ( 2 ). The ¹⁹⁵Pt NMR spectra from dichlormethane solutions exhibit each one sharp signal at 3975.6 ( 1 ) and 3231.6 ppm ( 2 ), respectively.     

Darstellung,Kristallstruktur, Schwingungsspektren und Normalkoordinatenanalyse von [Co(NH3)6][Os(SCN)6]

Synthesis, Crystal Structure, Vibrational Spectra, and Normal Coordinate Analysis of [Co(NH₃)₆][Os(SCN)₆] From the mixture of the linkage isomers [Os(NCS)_n(SCN)_6–n]^3–, n = 0–2, pure [Os(SCN)₆]^3– has been isolated by ion exchange chromatography on diethylaminoethyl cellulose. The X‐ray structure determination on a single crystal of [Co(NH₃)₆][Os(SCN)₆] (trigonal, space group R 3, a = 12.368(2), c = 11.830(2) Å, Z = 3) reveals that the thiocyanate ligands are exclusively S‐coordinated with the Os–S distance of 2.388 Å and the Os–S–C angle of 108.8°. The IR and Raman spectra of (n‐Bu₄N)₃[Os(SCN)₆] are assigned by normal coordinate analysis based on the molecular parameters of the X‐ray determination. The valence force constant f_d(OsS) is 1.42 mdyn/Å.     

Darstellung von Nonahalogenodiplatinaten(IV), [Pt2X9]−, X  Cl,Br Spektroskopische Charakterisierung,Normalkoordinatenanalyse und Kristallstruktur von (PPN)[Pt2Br9]

Preparation of the Nonahalogenodiplatinates(IV), [Pt₂X₉]^?, X ? Cl, Br Spectroscopic Characterization, Normal Coordinate Analysis, and Crystal Structure of (PPN)[Pt₂Br₉] On heating the tetrabutylammonium salts (TBA)₂[PtX₆], with trifluoroacetic acid the nonahalogenodiplatinates(IV) (TBA)[Pt₂X₉], with X ? Cl, Br are formed. The X-ray structure determination on (PPN)[Pt₂Br₉] (orthorhombic, space group Pca2, Z = 4) shows for the anions pairs of face-sharing octahedra with nearly D_3h symmetry. The mean terminal and bridging Pt? Br bond lengths are determined to be 2.42 and 2.52 Å, respectively. The electrostatic interaction of the Pt atoms results in the Pt? Pt distance of 3.23 Å and an elongation as it has been forecasted by the MO scheme for d⁶ systems. Using the structural data a normal coordinate analysis based on a general valence force field for [Pt₂Br₉]^? has been performed, revealing a good agreement of the calculated frequencies with the bands observed in the IR and Raman spectra. The stronger bonding of the terminal as compared to the bridging ligands is shown by the valence force constants, f_a(Br₁) = 1,55 > f_d(Br_b) = 0,93 mdyn/ Å.     

Kristallstruktur,Schwingungsspektrum und Normalkoordinatenanalyse von (PNP)2[ReFBr5] · H2O

Crystal Structure, Vibrational Spectrum, and Normal Coordinate Analysis of (PNP)₂[ReFBr₅] · H₂O From the complex mixture obtained by oxidative ligand exchange of [ReBr₆]^2– with BrF₃ [ReFBr₅]^2– has been isolated by ion exchange chromatography on diethylaminoethyl cellulose with 45% yield. The X-ray structure determination of (PNP)₂[ReFBr₅] · H₂O (monoclinic, space group P2₁/c with a = 21.498(2), b = 13.314(3), c = 23.945(2) Å, β = 105.235(7)°, Z = 4) reveals a completely ordered anion sublattice resulting from the solvent water linked to the F ligand by a hydrogen bond (O–F: 2.758(6) Å). Due to the stronger trans influence of Br compared with F on the F ^· –Re–Br′ axis the Re–Br′ distance is shortened by 0.6% with regard to symmetrically coordinated axes. Based on the molecular parameters of the X-Ray determination the low temperature (10 K) IR and Raman spectrum of the (Me₄N) salt is assigned by a normal coordinate analysis. The strengthening of the Re–Br′ bond due to the trans influence is indicated by an increase of the valence force constant f_d(ReBr′) = 1.43 by 8% as compared with f_d(ReBr) = 1.32 mdyn/Å of symmetric axes.     

Kristallstrukturen,Schwingungsspektren und Normalkoordinatenanalysen der stereoisomeren Trifluorotrichloroplatinate(IV), fac-[(C5H5N)2CH2][PtF3Cl3] · 0,5(CH3)2CO und mer-[(C5H5N)2CH2][PtF3Cl3]

Crystal Structures, Vibrational Spectra, and Normal Coordinate Analyses of the Stereoisomeric Trifluorotrichloroplatinates(IV), fac-[(C₅H₅N)₂CH₂][PtF₃Cl₃] · 0.5(CH₃)₂CO and mer-[(C₅H₅N)₂CH₂][PtF₃Cl₃] The geometric isomers fac- und mer-[PtF₃Cl₃]^2? have been isolated by ion exchange chromatography on diethylaminoethyl cellulose. The doubly charged complex anions form stable AB-type salts with the dication dipyridiniomethane, [(C₅H₅N)₂CH₂]²⁺. The X-ray structure determination on single crystals of fac-[(C₅H₅N)₂CH₂][PtF₃Cl₃] · 0,5(CH₃)₂CO ( 1 ) (triclinic, space group P1 with a = 8.468(3), b = 8.847(2), c = 12.1260(10) Å, α = 79.986(12), β = 79.009(12), γ = 69.20(3)°, Z = 2) and mer-[(C₅H₅N)₂CH₂][PtF₃Cl₃] ( 2 ) (monoclinic, space group P2₁/n with a = 9.620(2), b = 14.031(4), c = 10.435(3) Å, β = 97.54(2)°, Z = 4) reveals the perfect ordering of the anion sublattice. Due to the stronger trans influence of Cl compared to F in asymmetric axes $ {\rm F}^. $? Pt? Cl′ the Pt? $ {\rm F}^. $ distance is lengthened by 1.8%, the Pt? Cl′ distance is shortened by 1.2% in comparison with symmetrically coordinated axes. Correspondingly, the vibrational spectra exhibit shifts of the Pt$ {\rm F}^. $ streching vibrations by 8% to lower, and of the PtCl′ streching vibrations by 12% to higher frequencies. Normal coordinate analyses performed on the basis of the X-ray data result in valence force constants for weakened Pt? $ {\rm F}^. $ bonds to be 14% lower, for the strengthened Pt? Cl′ bonds to be 20% higher than in symmetric axes, respectively. Generally the trans influence in fluorochloroplatinates(IV) on the bond lengths is very low with 1–2%, it results in considerable shifts of the stretching vibrations by 8–12% and reveals the strongest effect on the valence force constants with 14–20%.     

Darstellung,Kristallstrukturen, Schwingungsspektren und Normalkoordinatenanalyse von vier bindungsisomeren Tetrachlorodirhodanoosmaten(IV)

Preparation, Crystal Structures, Vibrational Spectra, and Normal Coordinate Analysis of Four Linkage Isomeric Tetrachlorodirhodanoosmates(IV) By treatment of cis- or trans-[OsCl₄I₂]^2? with (SCN)₂ in dichloromethane the linkage isomers cis-[OsCl₄(NCS)₂]^2? ( 1 ), trans-[OsCl₄(NCS)(SCN)]^2? ( 2 ), cis-[OsCl₄(NCS)(SCN)]^2? ( 3 ) and trans-[OsCl₄(SCN)₂]^2? ( 4 ) are formed which have been separated by ion exchange chromatography on diethylaminoethyl cellulose. The X-Ray structure determinations on single crystals of cis-(Ph₄As)₂[OsCl₄(NCS)₂] (triclinic, space group P1 , a = 10.019(5), b = 11.702(5), c = 21.922(5) Å, α = 83.602(5)°, β = 85.718(5)°, γ = 73.300(5)°, Z = 2), trans-(Ph₄As)₂[OsCl₄ · (NCS)(SCN)] (monoclinic, space group P2₁/c, a = 18.025(5), b = 11.445(5), c = 23.437(5) Å, β = 94.208(5)°, Z = 4), cis-(Ph₄As)₂[OsCl₄(NCS)(SCN)] (triclinic, space group P1 , a = 10.579(5), b = 11.682(5), c = 22.557(5) Å, α = 81.073(5)°, β = 85.807(5)°, γ = 87.677(5)°, Z = 2) and trans-(Ph₄As)₂ · [OsCl₄(SCN)₂] (triclinic, space group P1 , a = 10.615(5), b = 11.691(5), c = 11.907(5) Å, α = 111.314(5)°, β = 96.718(5)°, γ = 91.446(5)°, Z = 1) reveal the complete ordering of the complex anions. The via N or S coordinated thiocyanate groups are located nearly direct above one of the cis-positioned Cl ligands with Os? N? C angles of 171.2° and 174.3° ( 1 ), 162.3° ( 2 ), 172° ( 3 ) and Os? S? C angles of 108.3° ( 2 ), 105.7° ( 3 ) and 105.5° ( 4 ). Using the molecular parameters of the X-Ray determinations the low temperature (10 K) IR and Raman spectra of the (n-Bu₄N) salts of all four linkage isomers are assigned by normal coordinate analyses based on a modified valence force field. The valence force constants are f_d(OsN) = 1.59 ( 1 ), 1.67 ( 2 ), 1.60 ( 3 ) and f_d(OsS) = 1.27 ( 2 ), 1.31 ( 3 ) and 1.32 mdyn Å^?1 ( 4 ). Taking into account increments of the trans influence a good agreement between observed and calculated frequencies is achieved.     

Kristallstrukturen,Schwingungsspektren und Normalkoordinatenanalysen von (n-Bu4N)2[ReBr5(NCS)] und (n-Bu4N)2[ReBr5(NCSe)]

Crystal Structures, Vibrational Spectra, and Normal Coordinate Analysis of ( n -Bu₄N)₂[ReBr₅(NCS)] and ( n -Bu₄N)₂[ReBr₅(NCSe)] The X-ray structure determinations on single crystals of (n-Bu₄N)₂[ReBr₅(NCS)] ( 1 ) (monoclinic, space group P2₁/n, a = 10.9860(9), b = 11.6860(7), c = 35.551(3) Å, β = 91.960(9)°, Z = 4) and (n-Bu₄N)₂[ReBr₅(NCSe)] ( 2 ) (monoclinic, space group P2₁/n, a = 11.0208(15), b = 11.7418(16), c = 35.621(12) Å, β = 92.003(18)°, Z = 4) reveal that the thiocyanate and the selenocyanate group are bonded with the Re–N–C angle of 168.5° ( 1 ) and 169.9° ( 2 ). Based on the molecular parameters of the X-ray determinations the IR and Raman spectra have been assigned by normal coordinate analysis. The valence force constants f_d(ReN) are 1.81 ( 1 ) and 1.75 mdyn/Å ( 2 ).     

Darstellung, 11B-NMR-, Schwingungsspektren und Kristallstruktur von [(C5H5N)2CH2][1-(O2N)B10H9]

Preparation, ¹¹B NMR, Vibrational Spectra, and Crystal Structure of [(C₅H₅N)₂CH₂][1-(O₂N)B₁₀H₉] By reaction of [B₁₀H₁₀]^2? in aqueous acetonitrile with a saturated solution of NO₂ in dichloromethane [1-(O₂N) · B₁₀H₉]^2? and [B₁₀H₉(NO)B₁₀H₉]^3? are formed which can be separated by ion exchange chromatography on diethylaminoethyl(DEAE) cellulose from the starting compound. The X-ray structure determination of [(C₅H₅N)₂CH₂][1-(O₂N)B₁₀H₉] (triclinic, space group P1 , a = 7.1530(9), b = 8.3753(8), c = 15.198(2) Å, α = 96.00(1), β = 95.48(1), γ = 95.60(1)°, Z = 2) reveals the coordination of the NO₂ group via N with a B1? N distance of 1.535(5) Å and an O2? N? O1 angle of 119.3(3)°. The ¹¹B NMR spectrum exhibits the characteristic feature (1 : 1 : 4 : 4) of an apical monosubstituted B₁₀ cluster with a strong downfield shift of the ipso-B atom at +13.4 ppm. The IR and Raman spectra show strong NO stretching vibrations at 1381 und 1420 cm^?1.     

Darstellung,spektroskopische Charakterisierung und Normalkoordinatenanalyse von Nonabromoditechnetat(IV), [Tc2Br9]−

Preparation, Spectroscopic Characterization and Normal Coordinate Analysis of Nonabromoditechnetate(IV), [Tc₂Br₉]^? . On heating the tetraethylammonium salt (TEA)₂[Tc₂Br₆] with trifluoroacetic acid the face-sharing bioctahedral anion [Tc₂Br₉]^? is formed, which vibronic spectrum is assigned according to point group D_3h. Normal coordinate analysis, based on a general valence force field has been performed, resulting in a good agreement of calculated frequencies with the observed IR and Raman bands. Due to stronger bonding of the terminal as compared to the bridging ligands, the valence force constant f_d(TcBr_t) = 1.045 is significantly higher than f_d(TcBr_b) = 0.80 mdyn/Å.     

Darstellung und Kristallstruktur von β-[SeCl3][MoOCl4]

Preparation and Crystal Structure of β-[SeCl₃][MoOCl₄] The reaction of Se₄[MoOCl₄] and Te₄[MoOCl₄] with SOCl₂ as solvent at 150 °C and 80 °C yields [SeCl₃][MoOCl₄] and [TeCl₃][MoOCl₄] respectively within 3 to 6 days as yellow-brown, moisture-sensitive crystals. [TeCl₃][MoOCl₄] was obtained in the already known monoclinic form, while β-[SeCl₃][MoOCl₄] crystallizes in a new polymorphic triclinic form (P1¯, Z = 2, a = 752.7(2), b = 812.8(2), c = 956.9(3) pm, α = 92.55(3)°, β = 111.63(2)°, γ = 107.39(3)°). The structure contains centrosymmetric tetranuclear units ([SeCl₃]₂[Mo₂O₂Cl₈]) which are analogous to the entities found in the structure of [SCl₃][MoOCl₄]. The packing of the molecules in β-[SeCl₃][MoOCl₄] and [SCl₃][MoOCl₄] is distinctely different.