Darstellung, Schwingungsspektren und Normalkoordinationsanalyse der D- und 13C-Isotopomeren des Methylpentahydro-closo-hexaborats [B6H5(CH3)]2- sowie Kristallstruktur von [P(C6H5)4][B6H6(CH3)] / Preparation, Vibrational Spectra and Normal Coordinate Analysis of the D and 13C Isotopomeres of the Methylpentahydro-closo-hexaborate [B6H5(CH3)]2- and the Crystal Structure of [P(C6H5)4][B6H6(CH3)]

1995 ◽  
Vol 50 (4) ◽  
pp. 623-629 ◽  
Author(s):  
J. Baurmeister ◽  
A. Franken ◽  
W. Preetz
Keyword(s):  
Crystal Structure ◽  
Normal Coordinate Analysis ◽  
Force Constants ◽  
Potential Energy Distribution ◽  
X Ray Diffraction ◽  
Normal Coordinate ◽  
Triclinic Space Group ◽  
Stretching Vibration ◽  
Ir And Raman ◽  
Good Agreement

The crystal structure of [P(C6H5)4][B6H6(CH3)] has been determined by single crystal X-ray diffraction analysis; triclinic space group P 1̄ with a = 7.408(2), b = 11.887(3), c = 14.4486(9) Å , α = 80.013(12), β = 79.421(10), γ = 88.85(2)°. The additional H atom could be refined with B - H distances between 1.21 and 1.31 Å above one of the facettes of the B6 octahedron adjacent to the methyl group. The IR and Raman spectra of the ueprotonated Cs salts of the six isotopomers [B6H5(CH3)]2-, [B6H5(CD3)]2-, [B6H5(13CH3)]2-, [B6D5(CH3)]2-, [B6D5(CD3)]2- and [B6D5(13CH3)]2- exhibit characteristic shifts of their vibration bands. Using the crystallographic data a normal coordinate analysis has been performed, based on a general valence force field. With a set of 14 force constants (e.g. fd(BB ) = 1.80, fd(BC ) = 3.70, fd(BH ) = 3.17, fd(CH ) = 4.62 mdyn/Å) good agreement between observed and calculated frequencies o f all D and 13C isotopically labeled derivatives has been achieved. The potential energy distribution on the force constants reveals strong vibrational couplings of the boron cage with the substituents. The B - C stretching vibration o f the CH3 group is observed in the region 1142-1153 cm-1, for the CD3 substituent at higher frequencies of 1168-1179 cm-1.

Darstellung, Schwingungsspektren und Normalkoordinatenanalyse der 10B-und 11B-Isotopomeren von [B2(NCS)6]2- sowie Kristallstruktur von (Ph3P=N=PPh3)2[B2(NCS)6] / Preparation, Vibrational Spectra and Normal Coordinate Analysis of the 10B and 11B Isotopomers of [B2(NCS)6]2- and Crystal Structure of (Ph3P=N=PPh3)2[B2(NCS)6]

1996 ◽  
Vol 51 (4) ◽  
pp. 551-556 ◽  
Author(s):  
W. Preetz ◽  
B. Steuer
Keyword(s):  
Crystal Structure ◽  
Normal Coordinate Analysis ◽  
Force Constants ◽  
Potential Energy Distribution ◽  
X Ray Diffraction ◽  
Normal Coordinate ◽  
Triclinic Space Group ◽  
X Ray ◽  
Fractionated Crystallization ◽  
Good Agreement

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.

Darstellung, Kristallstruktur, Schwingungsspektren und Normalkoordinatenanalyse von [Os(acac)3]/ Synthesis, Crystal Structure, Vibrational Spectra, and Normal Coordinate Analysis of [Os(acac)3]

1998 ◽  
Vol 53 (2) ◽  
pp. 232-238 ◽  
Author(s):  
K. Dallmann ◽  
W. Preetz
Keyword(s):  
Crystal Structure ◽  
Normal Modes ◽  
Normal Coordinate Analysis ◽  
Force Constants ◽  
X Ray Diffraction ◽  
Normal Coordinate ◽  
X Ray ◽  
Modes Of Vibration ◽  
Ir And Raman ◽  
Good Agreement

Abstract In the reaction of K2[OsCl6] with boiling water/acetylacetone (1:1) a mixture of different chloro-acetylacetonato complexes is formed, from which [Os(acac)3] can be isolated by column chromatography with dichloromethane on silica gel. The crystal structure of [Os(acac)3] (mo­noclinic, space group P21/c,a = 13.968(5), b = 7.517(5), c = 16.455(5) Å ,β = 98.939(5)°, Z = 4) has been determined by single crystal X-ray diffraction analysis. High resolution IR and Raman spectra were measured at low temperature (10K). Based on the molecular parameters of the X-ray structure determination a normal coordinate analysis has been performed and the normal modes of vibration have been assigned. With a set of 32 force constants, taking into account the intraligand vibrations, a good agreement between observed and calculated frequencies has been achieved. The valence force constants are fd(OsO) = 3.19 and fd(OC) = 6.74 mdyn/Å.

Darstellung, Schwingungsspektren und Normalkoordinatenanalyse von (n-Bu4N)2[Pt(SCN)n(ox)], n = 2, 4, sowie Kristallstruktur von [(C5H5N)2CH2][Pt(SCN)4(ox)] / Synthesis, Vibrational Spectra and Normal Coordinate Analysis of (n-Bu4N)2[Pt(SCN)n(ox)], n = 2, 4, and Crystal Structure of [(C5H5N)2CH2][Pt(SCN)4(ox)]

2002 ◽  
Vol 57 (9) ◽  
pp. 1036-1042 ◽  
Author(s):  
J.-G. Uttecht ◽  
C. Nöther ◽  
W. Preetz
Keyword(s):  
Crystal Structure ◽  
Vibrational Spectra ◽  
Normal Coordinate Analysis ◽  
Normal Coordinate ◽  
Photochemical Reduction ◽  
Triclinic Space Group ◽  
X Ray ◽  
Trans Influence ◽  
Ir And Raman ◽  
Good Agreement

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)

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
Keyword(s):  
Crystal Structure ◽  
Aqueous Solution ◽  
Vibrational Spectra ◽  
Room Temperature ◽  
Normal Coordinate Analysis ◽  
X Ray Diffraction ◽  
Normal Coordinate ◽  
Triclinic Space Group ◽  
X Ray ◽  
Ir And Raman

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.

Kristallstrukturen, Schwingungsspektren und Normalkoordinatenanalyse von cis-[ReCl4X2]2-, X = NCS, NCSe / Crystal Structures, Vibrational Spectra and Normal Coordinate Analysis of cis-[ReCl4X2]2-, X = NCS, NCSe

1998 ◽  
Vol 53 (11) ◽  
pp. 1329-1334 ◽  
Author(s):  
L. Homolya ◽  
S. Strueß ◽  
W. Preetz
Keyword(s):  
Crystal Structures ◽  
Normal Coordinate Analysis ◽  
X Ray Diffraction ◽  
Normal Coordinate ◽  
Triclinic Space Group ◽  
Valence Force ◽  
Space Group ◽  
X Ray ◽  
Valence Force Field ◽  
Ir And Raman

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.

Darstellung und Schwingungsspektren von cis- und trans-[OsXY(acac)2], X ≠ Y = Cl, Br, I sowie Normalkoordinatenanalyse von trans-[OsClBr(acac)2]/Synthesis and Vibrational Spectra of cis- and trans-[OsXY(acac)2], X ≠ Y = Cl, Br, I, and Normal Coordinate Analysis of trans-[OsClBr(acac)2]

1998 ◽  
Vol 53 (2) ◽  
pp. 227-231
Author(s):  
K. Dallmann ◽  
W. Preetz
Keyword(s):  
Normal Coordinate Analysis ◽  
Force Constants ◽  
Vibrational Modes ◽  
Normal Coordinate ◽  
Valence Force ◽  
Valence Force Field ◽  
Stretching Vibrations ◽  
Cis And Trans ◽  
Ir And Raman ◽  
Good Agreement

Abstract In the reaction of K2[OsX3 Y3] with boiling water/acetylacetone (1:1) the six mixed com­plexes cis-and trans-[OsX2 (acac)2] (X ≠ Y = Cl, Br, I) are formed, which have been purified by column chromatography with toluene on silica gel. The IR and Raman spectra (10K) show the intraligand vibrations of the acac groups with nearly constant frequencies and the stretching vibrations of OsO in the range 460-696, of OsCl at 315-345, of OsBr at 210-225, and of Osl at 160-175 cm-1 . A normal coordinate analysis based on a modified valence force field was performed for trans-[OsClBr(acac)2] and the vibrational modes have been assigned. With a set of 32 force constants, taking into account the intraligand vibrations, a good agreement between observed and calculated frequencies has been achieved. The valence force constants are fd (OsCl•) = 1.75, fd(OsBr′) = 1.63 and fd (OsO) = 3.27 mdyn/Å.

Kristallstrukturen von [P(C6H5)4]2[B6Cl6](CH3CN)2 und [P(C6H5)4]2[B6Br6](CH3CN)2 sowie Schwingungsspektren und Normalkoordinatenanalyse der isotopomeren closo-Hexahalogenohexaborate [11Bn10B6-nX6]2-, Χ = Cl, Br; n = 0-6 / Crystal Structures of [P(C6H5)4]2[B6Cl6](CH3CN)2 and [P(C6H5)4]2[B6Br6](CH3CN)2, Vibrational Spectra and Normal Coordinate Analysis of Isotopomeric closo-Hexahalogenohexaborates [11Bn10B6-nX6]2-, X = Cl, Br; n = 0-6

1991 ◽  
Vol 46 (6) ◽  
pp. 800-808 ◽  
Author(s):  
J. Thesing ◽  
J. Baurmeister ◽  
W. Preetz ◽  
D. Thiery ◽  
H. G. von Schnering
Keyword(s):  
Crystal Structures ◽  
Molecular Data ◽  
Force Constants ◽  
Geometric Isomers ◽  
X Ray Diffraction ◽  
Normal Coordinate ◽  
Vibrational Coupling ◽  
Triclinic Space Group ◽  
Bond Lengths ◽  
Good Agreement

The crystal structures of (TPP)2[B6Cl6](CH3CN)2 and (TPP)2[B6Br6](CH3CN)2 were determined from single crystal X-ray diffraction analyses at 147 K. They are triclinic, space group P1̅, and contain nearly regular octahedral anions with bond lengths d(B-B) 1.716, d(B-Cl) 1.818 for [B6Cl6]2- and d̅(B-B) 1.684, d̅(B-Br) 1.993 Å for [B6Br6]2-. Using these molecular data, normal coordinate analyses for the ten isotopomers [11Bn10B6-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. With a set of 8 force constants for Cs2[B6Br6] (e.g. fd(BB) = 1.39, fd(BBr) = 3.18 mdyn/Å) and 10 for Cs2[B6Cl16] (e. g. fd(BB) = 1.30, fd(BCl) = 4.01 mdyn/Å) the calculated frequencies are in good agreement with observed IR (10 K) and Raman bands (80 K) in natural abundance as well as for 11B- and 10B-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.

Schwingungsspektren und Normalkoordinatenanalysen der Dioxoosmate( VI) trans-[OsO2(CN)4]2-, trans-[OsO2(CN)2(0H )]22- und trans-[OsO2(CN)2(OCH3)]22 sowie Kristallstruktur von trans-(Ph3PNPPh3)2[OsO2(CN)2(OCH3)]2 / Vibrational Spectra and Normal Coordinate Analysis of the Dioxoosmates(VI) trans-[OsO2(CN)4]2-, trans-[OsO2 (CN)2(OH)]22- and trans-[OsO2(CN)2(OCH3]22- , and Crystal Structure of trans-(Ph3PNPPh3)2[OsO2(CN)2(OCH3)]2

1999 ◽  
Vol 54 (9) ◽  
pp. 1109-1115
Author(s):  
A. Strueß ◽  
W. Preetz
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Diffraction Analysis ◽  
Vibrational Spectra ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
Normal Coordinate ◽  
Triclinic Space Group ◽  
X Ray ◽  
Ir And Raman

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

Darstellung, 11B-NMR-Spektren, Schwingungsspektren und Normalkoordinatenanalyse von conjuncto-Bis-hexahydro-closo-hexaborat, [B6H6-B6H6]2-, sowie Kristallstruktur von [P(C6H5)4]2-conjuncto-[B6H6-B6H6] / Preparation, 11B NMR Spectra, Vibrational Spectra and Normal Coordinate Analysis of conjuncto-Bis-hexahydro-closo-hexaborate, [B6H6-B6H6]2-, and the Crystal Structure of [ P(C6H5)4]2-conjuncto-[B6H6-B6H6]

1996 ◽  
Vol 51 (5) ◽  
pp. 609-618 ◽  
Author(s):  
D. Bublitz ◽  
A. Franken ◽  
W. Preetz ◽  
H. Thomsen
Keyword(s):  
Crystal Structure ◽  
Exchange Chromatography ◽  
X Ray Diffraction ◽  
Normal Coordinate ◽  
Vibrational Coupling ◽  
Nmr Spectrum ◽  
Triclinic Space Group ◽  
Diethylaminoethyl Cellulose ◽  
11B Nmr ◽  
Ir And Raman

By reaction of [B6H6]2- with dibenzoylperoxide in dichloromethane conjuncto-[B6H6- B6H6]2- is formed. The product could be separated from excess [B6H6]2- by ion exchange chromatography on diethylaminoethyl cellulose. The crystal structure of [P(C6H5)4]2 -conjuncto- [B6H6-B6H6] has been determined by single crystal X-ray diffraction analysis; triclinic, space group P1̄ with a = 10.8315(10), b = 11,2422( 12), c = 20.340(2) Å, α = 91.278° (9), β = 90.178° (9), γ = 105.662°(9). The 11B NMR spectrum reveals three signals with the intensity ratio 1:1:4, for two equivalent moieties of the conjuncto molecule ion with local C4v symmetry. The IR and Raman spectra of the deprotonated Cs salts of the 10B, 11B and their respective D isotopomers of conjuncto-[B6H5-B6H5]4- exhibit characteristic shifts. Using averaged crystallographic data and assuming idealized D4h symmetry, normal coordinate analyses have been performed based on a modified valence force field. With a set of eleven force constants (e.g. fd(BB)conjuncto = 2.9, fd(BB)cage = 1.6 mdyn/Å) very good agreement between observed and calculated frequencies has been achieved. From strong vibrational coupling with the B6 clusters two vibrations result for the conjuncto B-B bond at 1142/1198 and 292/304cm-1 for 11B/10B species, respectively. They can be assigned as anti-phase and in-phase motions of the conjuncto B atoms related to the equatorial B4 planes.

Darstellung, 11B-, 13C-, 29Si-NMR- und Schwingungsspektren von Trimethylsilylmethyl-hexahydro-closo-hexaborat, [B6H6(CH2Si(CH3)3)]- sowie Kristallstruktur von [P(C6H5)4][B6H6(CH2Si(CH3)3)] / Preparation, 11B, 13C, 29Si NMR and Vibrational Spectra of Trimethylsilylmethyl-hexahydro-clo-hexaborate, [B6H6(CH2Si(CH 3)3)]-and the Crystal Structure of [P(C6H5)4] [B6H6(CH2Si(CH3)3)]

1995 ◽  
Vol 50 (7) ◽  
pp. 1025-1029 ◽  
Author(s):  
J. Baurmeister ◽  
A. Franken ◽  
W. Preetz
Keyword(s):  
Crystal Structure ◽  
Monoclinic Space Group ◽  
29Si Nmr ◽  
X Ray Diffraction ◽  
Nmr Spectrum ◽  
X Ray ◽  
Quadrupole Coupling ◽  
Stretching Vibration ◽  
Ir And Raman ◽  
C Nmr

By reaction of [N(C4H9 )4]2 [B6H6] with iodomethyl-trimethylsilane in acetonitrile a solution with trimethylsilylm ethyl-closo-hexaborate(1-)anions, [B6H6 (CH2Si(CH3)3)]-, is formed. The crystal structure of [P(C6H5 )4][B6H6(CH2Si(CH3)3)] has been determined by single crystal X-ray diffraction analysis; monoclinic, space group P21/n with a = 16.140(2), b = 11.646(8), c = 16.731(3) Å, β 109.664(11)°. The 11B NMR spectrum reveals features of a mono hetero substituted octahedral B6 cage. The 13C NMR spectrum exhibits a quartet at +0.18 ppm with 1J(C,H) = 118 Hz for the three methyl groups and a weak multiplet at -0.65 ppm for the methylene bridge due to quadrupole coupling with the boron atoms. In the 29Si NMR spectrum a decet at +2.25 ppm with 2J(C,H ) = 6.9 Hz is observed. The B -C stretching vibration is observed at 1155 cm-1 in the IR and Raman spectrum.

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