The structure and acid–base properties of methyl and silyl amines and phosphines: An ab-initio SCF study

The structures of the methyl and silyl amines and phosphines and their ions have been calculated using ab-initio SCF theory and the 3-21G basis set. The computed structures give excellent agreement with the available experiment data without the inclusion of d functions, with the exception of (SiH₃)₂N– and the isoelectronic molecules (SiH₃)₂O and (SiH₃)₂C^2? where d functions are essential. The observed trends in computed basicities and acidities are reproduced by the calculations.     

Geminal interactions in ClZ(CH3)2X molecules (Z = C, Si, Ge) according to ab initio calculations

The structure and electronic parameters of ClZ(CH₃)₂X molecules (Z = C, Si, Ge, X = CH₃, OCH₃) were calculated by the RHF/6–31G(d) and RHF/6–311G(d,p) methods with full geometry optimization; calculations of ClZ(CH₃)₂OCH₃ molecules were also performed by the RHF/6–31G(d) method with partial geometry optimization. The ³⁵Cl NQR frequencies calculated from the populations of less diffuse 3p constituents of valence p orbitals of chlorine [RHF/6–31G(d)] were in agreement with the experimental values. The ³⁵Cl NQR frequencies for molecules with X = OCH₃ are lower than those for molecules with X = CH₃ (the Z atom being the same), due mainly to direct through-field polarization of the Z-Cl bond, induced by the effect of unshared electron pair of the oxygen atom in the trans position with respect to that bond. The difference in the ³⁵Cl NQR frequencies decreases in going from Z = C to Z = Si, Ge, in parallel with variation of the Z-Cl bond polarization as the size of Z increases.     

Darstellung,Kristallstrukturen, Schwingungsspektren und Normalkoordinatenanalysen der Tetrahalogeno‐bis‐Pyridin‐Osmium(III)‐Komplexe cis‐(n‐Bu4N)[OsCl4Py2] und trans‐(n‐Bu4N)[OsX4Py2], X = Cl,Br

Synthesis, Crystal Structures, Vibrational Spectra, and Normal Coordinate Analyses of the Tetrahalogeno‐bis‐Pyridine‐Osmium(III) Complexes cis ‐( n ‐Bu₄N)[OsCl₄Py₂] and trans ‐( n ‐Bu₄N)[OsX₄Py₂], X = Cl, Br By reaction of (n‐Bu₄N)₂[OsX₆], X = Cl, Br, with pyridine and (n‐Bu₄N)[BH₄] tetrahalogeno‐bis‐pyridine‐osmium(III) complexes are formed and purified by chromatography. X‐ray structure determinations on single crystals have been performed of cis‐(n‐Bu₄N)[OsCl₄Py₂] ( 1 ) (triclinic, space group P1, a = 9.4047(9), b = 10.8424(18), c = 17.007(2) Å, α = 71.833(2), β = 81.249(10), γ = 67.209(12)°, Z = 2), trans‐(n‐Bu₄N)[OsCl₄Py₂] ( 2 ) (orthorhombic, space group P2₁2₁2₁, a = 8.7709(12), b = 20.551(4), c = 17.174(4) Å, Z = 4) and trans‐(n‐Bu₄N)[OsBr₄Py₂] ( 3 ) (triclinic, space group P1, a = 9.132(3), b = 12.053(3), c = 15.398(2) Å, α = 95.551(18), β = 94.12(2), γ = 106.529(19)°, Z = 2). Based on the molecular parameters of the X‐ray structure determinations and assuming C₂ point symmetry for the anion of 1 and D_2h point symmetry for the anions of 2 and 3 the IR and Raman spectra are assigned by normal coordinate analysis. The valence force constants of 1 are in the Cl–Os–Cl axis f_d(OsCl) = 1.58, in the asymmetrically coordinated N′–Os–Cl ^· axes f_d(OsCl ^· ) = 1.45, f_d(OsN′) = 2.48, of 2 f_d(OsCl) = 1.62, f_d(OsN) = 2.42 and of 3 f_d(OsBr) = 1.39 and f_d(OsN) = 2.34 mdyn/Å.     

Darstellung,Kristallstrukturen, Schwingungsspektren und Normalkoordinatenanalyse von (n‐Bu4N)2[PtX4(ox)], X = Cl,BR

Synthesis, Crystal Structure, Vibrational Spectra, and Normal Coordinate Analysis of (n‐Bu₄N)₂[PtX₄(ox)], X = Cl, Br By oxidation of (n‐Bu₄N)₂[PtX₂(ox)], X = Cl, Br, with Cl₂ or Br₂ in dichloromethane (n‐Bu₄N)₂[PtCl₄(ox)] ( 1 ) and (n‐Bu₄N)₂[PtBr₄(ox)] ( 2 ) are formed. The crystal structure of [(C₅H₅N)₂CH₂][PtCl₄(ox)] (monoclinic, space group C2/m, a = 15.562(1), b = 13.779(1), c = 10.168(1)Å, ß = 128.099(9)°, Z = 4) reveals complex anions with nearly C_2v point symmetry. The bond lengths in the Cl′‐Pt‐O^˙ axes are Pt‐Cl′ = 2.287 and Pt‐O^˙ = 2.048 and in the Cl‐Pt‐Cl axis Pt‐Cl = 2.314Å. The oxalato ligand is nearly plane with an O‐C‐C‐O torsion angle of 0.5°. In the vibrational spectra the PtX stretching vibrations are observed at 328 and 353 ( 1 ) and 201 and 212 cm^—1 ( 2 ). The PtX′ modes appear at 360 and 343 ( 1 ) and 227 and 238 cm^—1 ( 2 ). The PtO^˙ stretching vibrations are coupled with internal modes of the oxalato ligands and appear in the range of 400—800 cm^—1. Based on the molecular parameters of the X‐ray determination ( 1 ) and estimated data ( 2 ) the IR and Raman spectra are assigned by normal coordinate analysis. The valence force constants are f_d(PtCl) = 2.08, f_d(PtCl′) = 2.29, f_d(PtBr) = 1.56, f_d(PtBr′) = 2.02 and f_d(PtO^˙) = 2.46 ( 1 ) and 2.35 mdyn/Å ( 2 ). Taking into account increments of the trans influence a good agreement between observed and calculated frequencies is achieved. The NMR shifts are δ(¹⁹⁵Pt) = 5623.0 ( 1 ) and 4536.1 ( 2 ).     

Bond dissociation energies and radical heats of formation in CH3Cl,CH2Cl2, CH3Br,CH2Br2, CH2FCl,and CHFCl2

An analysis of thermochemical and kinetic data on the bromination of the halomethanes CH_4–nX_n (X = F, Cl, Br; n = 1–3), the two chlorofluoromethanes, CH₂FCl and CHFCl₂, and CH₄, shows that the recently reported heats of formation of the radicals CH₂Cl, CHCl₂, CHBr₂, and CFCl₂, and the C? H bond dissociation energies in the matching halomethanes are not compatible with the activation energies for the corresponding reverse reactions. From the observed trends in CH₄ and the other halomethanes, the following revised ΔH°_f,298 (R) values have been derived: ΔH°_f(CH₂Cl) = 29.1 ± 1.0, ΔH°_f(CHCl₂) = 23.5 ± 1.2, ΔH_f(CH₂Br) = 40.4 ± 1.0, ΔH°_f(CHBr₂) = 45.0 ± 2.2, and ΔH°_f(CFCl₂) = ?21.3 ± 2.4 kcal mol^?1. The previously unavailable radical heat of formation, ΔH°_f(CHFCl) = ?14.5 ± 2.4 kcal mol^?1 has also been deduced. These values are used with the heats of formation of the parent compounds from the literature to evaluate C? H and C? X bond dissociation energies in CH₃Cl, CH₂Cl₂, CH₃Br, CH₂Br₂, CH₂FCl, and CHFCl₂.     

Schwingungsspektroskopische Untersuchungen an den Organohydrogensilanen (XCH2)(CH3)2SiH (X = Cl,Br, J), X(YO)2SiH (X = CH3, C2H5/Y = CH3, C2H5 … tert.-C4H9), (C6H5)2SiH2 und C6H5SiH3

Infrared and Raman Spectroscopic Investigations on the Organosubstituted Silicon Hydrides (XCH₂)(CH₃)₂SiH (X = Cl, Br, J), X(YO)₂SiH (X = CH₂, C₂H₅/Y = CH₃, C₂H₅ … tert.-C₄H₉), (C₆H₅)₂SiH₂ and C₆H₅SiH₃ Typical band splittings, specially for the SiH stretching vibration, are shown in the infrared and Raman spectra of the silicon hydrides (XCH₂)(CH₃)₂SiH (X = Cl, Br, J), and X(YO)₂SiH (X = CH₃, C₂H₅/Y = CH₃, C₂H₅ … tert.-C₄H₉). The cause of this behavior is in all probability the existence of rotational isomers. Raman polarization measurements at organosubstituted silicon di- and trihydrides demonstrate the accidental degeneracy of the SiH valence vibrations.     

Mono- and bis-alkoxides of tris(3,5-dimethylpyrazolyl)borato molybdenum and tungsten nitrosyls

The complexes [ML^*(NO)Cl(OR)] {L^* = HB(3,5-Me₂C₃HN₂)₃; M= Mo, R = CH₂CH₂X, X = Cl, OMe or OEt; (CH₂)_nOH, n = 2, 5, 6; M = W, R = CH₂CH₂X, X = Cl, OMe or OEt; (CH₂)_nOH, n = 2–6; CH₂(CF₂)₃CH₂OH; CHMeCH₂CMe₂OH} and [ML^*(NO)(OR)₂] {M = Mo, R = CH₂CH₂X, X = Cl, OMe or OEt; (CH₂)_nOH, n = 2–6; M = W,R = CH₂CH₂X, X= Cl, OMe or OEt; (CH₂)_nOH, n = 2,4–6; CH₂(CF₂)₃CH₂OH} have been prepared from [ML^*(NO)Cl₂] and the appropriate alcohol in the presence of NEt₃ or NaCO₃, and have been characterized by IR, ¹H NMR and mass spectroscopy.     

Silicon‐ and Tin‐Containing Open‐Chain and Eight‐Membered‐Ring Compounds as Bicentric Lewis Acids toward Anions

Herein, we report the syntheses of silicon‐ and tin‐containing open‐chain and eight‐membered‐ring compounds Me₂Si(CH₂SnMe₂X)₂ ( 2 , X=Me; 3 , X=Cl; 4 , X=F), CH₂(SnMe₂CH₂I)₂ ( 7 ), CH₂(SnMe₂CH₂Cl)₂ ( 8 ), cyclo‐Me₂Sn(CH₂SnMe₂CH₂)₂SiMe₂ ( 6 ), cyclo‐(Me₂SnCH₂)₄ ( 9 ), cyclo‐Me_(2?n)X_nSn(CH₂SiMe₂CH₂)₂SnX_nMe_(2?n) ( 5 , n=0; 10 , n = 1, X= Cl; 11 , n=1, X= F; 12 , n=2, X= Cl), and the chloride and fluoride complexes NEt₄[cyclo‐ Me(Cl)Sn(CH₂SiMe₂CH₂)₂Sn(Cl)Me?F] ( 13 ), PPh₄[cyclo‐Me(Cl)Sn(CH₂SiMe₂CH₂)₂Sn(Cl)Me?Cl] ( 14 ), NEt₄[cyclo‐Me(F)Sn(CH₂SiMe₂CH₂)₂Sn(F)Me?F] ( 15 ), [NEt₄]₂[cyclo‐Cl₂Sn(CH₂SiMe₂CH₂)₂SnCl₂?2 Cl] ( 16 ), M[Me₂Si(CH₂Sn(Cl)Me₂)₂?Cl] ( 17 a , M=PPh₄; 17 b , M=NEt₄), NEt₄[Me₂Si(CH₂Sn(Cl)Me₂)₂?F] ( 18 ), NEt₄[Me₂Si(CH₂Sn(F)Me₂)₂?F] ( 19 ), and PPh₄[Me₂Si(CH₂Sn(Cl)Me₂)₂?Br] ( 20 ). The compounds were characterised by electrospray mass‐spectrometric, IR and ¹H, ¹³C, ¹⁹F, ²⁹Si, and ¹¹⁹Sn NMR spectroscopic analysis, and, except for 15 and 18 , single‐crystal X‐ray diffraction studies.     

Synthese von methyldihalogenarsinen CH3AsXY mit verschiedenen halogenen XY

The reactions of the methylhalogenodimethylaminoarsines CH₃As-[N(CH₃)₂]X (X  F, Cl, Br, I) with HY (Y = Cl, Br) yield the methyldihalogenoarsines CH₃AsXY. The compounds CH₃As[N(CH₃)₂]X are prepared by the reactions of CH₃AsCl₂ with HN(CH₃)₂, CH₃As[N(CH₃)₂]₂ with HX (X = Cl, Br) and by exchange reactions between CH₃As[N(CH₃)₂]₂ and CH₃AsX₂ (X = F, Cl, Br, I).     

Electronic Effects in X(CH2)nY Homologous Series by NMR and Quantum Chemistry

The ^79,81Br NQR spectra of compounds of the Br(CH₂) _n COOH (n = 1-5) and Br(CH₂) _n COOSi·(CH₃)₃ (n = 1, 2, 4, 5) homologous series were measured at 77 K. The NQR frequencies of compounds of the first series as n increases to 3 and then oscillate. The ³⁵Cl NQR frequencies of Cl(CH₂) _n Cl series molecules, estimated from the Cl3p populations resulting from RHF/6-31G(d) calculations, steadily decrease as n increases from 1 to 10. No oscillation of calculated ³⁵Cl frequencies was revealed for compounds of the latter series (by contrast to experimental observations). The calculation results give no way to deducing the mechanism of the oscillation effect.     

Darstellung,Kristallstrukturen und Schwingungsspektren von trans‐[Pt(N3)4X2]2–, X = Cl,Br, I

Synthesis, Crystal Structures, and Vibrational Spectra of trans ‐[Pt(N₃)₄X₂]^2–, X = Cl, Br, I By oxidative addition to (n‐Bu₄N)₂[Pt(N₃)₄] with the elemental halogens in dichloromethane trans‐(n‐Bu₄N)₂[Pt(N₃)₄X₂], X = Cl, Br, I are formed. X‐ray structure determinations on single crystals of trans‐(Ph₄P)₂[Pt(N₃)₄Cl₂] (triclinic, space group P1, a = 10.352(1), b = 10.438(2), c = 11.890(2) Å, α = 91.808(12), β = 100.676(12), γ = 113.980(10)°, Z = 1), trans‐(Ph₄P)₂[Pt(N₃)₄Br₂] (triclinic, space group P1, a = 10.336(1), b = 10.536(1), c = 12.119(2) Å, α = 91.762(12), β = 101.135(12), γ = 112.867(10)°, Z = 1) and trans‐(Ph₄P)₂[Pt(N₃)₄I₂] (triclinic, space group P1, a = 10.186(2), b = 10.506(2), c = 12.219(2) Å, α = 91.847(16), β = 101.385(14), γ = 111.965(18)°, Z = 1) reveal, that the compounds crystallize isotypically with octahedral centrosymmetric complex anions. The bond lengths are Pt–Cl = 2.324, Pt–Br = 2.472, Pt–I = 2.619 and Pt–N = 2.052–2.122 Å. The approximate linear Azidoligands with N^α–N^β–N^γ‐angles = 172.1–176.8° are bonded with Pt–N^α–N^β‐angles = 116.2–121.9°. In the vibrational spectra the platinum halogen stretching vibrations of trans‐(n‐Bu₄N)₂[Pt(N₃)₄X₂] are observed in the range of 327–337 (X = Cl), at 202 (Br) and in the range of 145–165 cm^–1 (I), respectively. The platinum azide stretching modes of the three complex salts are in the range of 401–421 cm^–1. Based on the molecular parameters of the X‐ray determinations the IR and Raman spectra are assigned by normal coordinate analysis. The valence force constants are f_d(PtCl) = 1.90, f_d(PtBr) = 1.64, f_d(PtI) = 1.22, f_d(PtN^α) = 2.20–2.27 and f_d(N^αN^β, N^βN^γ) = 12.44 mdyn/Å.     

Ab Initio Calculations Show How 31PNMR Chemical Shifts in PXYZ Phosphines Correlate with Substituent Electronegativity

Abstract

Letcher and Van Wazers suggestion[1] that the ³¹P NMR chemical shifts of phosphines might be related to the substituent electronegativity, EN(X)[2], has not been verified subsequently by the available experimental data[3,4]. We now have explored this relationship systematically by means of reliable[5] ab initio magnetic property calculations[6] on a comprehensive set of molecules: PXY2 (Y= H, F, CH₃, Cl) and PXYZ (Y= H, Cl and Z= F) with X= H, CH₃, NH₂, OH, F, SiH₃, PH₂, SH, Cl.     

The gas-phase decomposition of methylsilane. Part III. Kinetics

The homogeneous gas-phase decomposition kinetics of methylsilane and methylsilane-d₃ have been investigated by the comparative-rate-single-pulse shock-tube technique at total pressures of 4700 torr in the 1125–1250 K temperature range. Three primary processes occur: CH₃SiH₃ → CH₃SiH + H₂ (1), CH₃SiH₃ → CH₄ + SiH₂ (2), and CH₃SiH₃ → CH₂ = SiH₂ + H₂ (3). The high-pressure rate constants for the primary processes in CH₃SiH₃ obtained by RRKM calculations are log (k₁ + k₃) (s^?1) = 15.2 - 64,780 Cal/θ and log k₂ (s^?) = 14.50 - 67,600 → 2800 Cal/θ. For CH₃SiD₃ these same rate constants are log k₁ (s^?) = 14.99 - 64,700 cal/θ log k₂ (s^?) = 14.68 – 66,700 → 2000 cal/θ, and log k₃ (s^?) = 14.3 ? 64,700 cal/θ.     

Magnesiumphthalocyanine: Darstellung und Eigenschaften von Halogenophthalocyaninatomagnesat, [Mg(X)Pc2−]− (X = F,Cl, Br); Kristallstruktur von Bis(triphenylphosphin)iminiumchloro(phthalocyaninato)magnesat-Aceton-Solvat

Magnesium Phthalocyanines: Synthesis and Properties of Halophthalocyaninatomagnesate, [Mg(X)Pc^2?]^? (X = F, Cl, Br); Crystal Structure of Bis(triphenylphosphine)iminiumchloro-(phthalocyaninato)magnesate Acetone Solvate Magnesium phthalocyanine reacts with excess tetra(n-butyl)ammonium- or bis(triphenylphosphine)iminiumhalide ((ⁿBu₄N)X or (PNP)X; X = F, Cl, Br) yielding halophthalocyaninatomagnesate ([Mg(X)Pc^2?]^?; X = F, Cl, Br), which crystallizes in part as a scarcely soluble (ⁿBu₄N) or (PNP) complex-salt. Single-crystal X-ray diffraction analysis of ^b(PNP)[Mg(Cl)Pc^2?] · CH₃COCH₃ reveals that the Mg atom has a tetragonal pyramidal coordination geometry with the Mg atom displaced out of the center (Ct) of the inner nitrogen atoms (N_iso) of the nonplanar Pc ligand toward the Cl atom (d(Mg? Ct) = 0.572(3) Å; d(Mg? Cl) = 2.367(2) Å). The average Mg? N_iso distance is 2.058 Å. Pairs of partially overlapping anions are present. The cation adopts a bent conformation (^b(PNP)⁺: d(P1? N(K)) = 1.568(3) Å; d(P2? N(K)) = 1.587(3) Å; ?(P1? N(K)? P2) = 141.3(2)°). Electrochemical and spectroscopic properties are discussed.     

Dimolybdenum Complexes Containing Pairs of Bridging Diphosphine and Carboxylate Ligands. Synthesis and Structures of trans-Mo2(O2CCH3)2(μ-dppa)2(BF4)2 and trans-Mo2X2(O2C(CH2)nCH3)2(μ-dppa)2 (n = 2, 10 or 12; X = Cl or Br; dppa = N,N-Bis(diphenylphosphino)amine)

The red complex trans-Mo₂(O₂CCH₃)₂(μ-dppa)₂(BF₄)₂, 1 , was prepared by reaction of [Mo₂(O₂CCH₃)₂(CH₃CN)₆][BF₄]₂ with dppa (dppa = Ph₂PN(H)PPh₂) in THF. The reactions of Mo₂(O₂C(CH₂)_nCH₃)₄ with dppa and (CH₃)₃SiX (X = Cl or Br) afforded the complexes trans-Mo₂X₂(O₂C(CH₂)_nCH₃)₂(μ-dppa)₂ (X = Cl, n = 2, 2; X = Br, n = 2, 3; X = Cl, n = 10, 4 ; X = Cl, n = 12, 5 ). Their UV-vis, IR and ³¹P{¹H}-NMR spectra have been recorded and the structures of 1, 2 and 3 have been determined. Crystal data for 1 : space group P2₁/n, a = 12.243(1) Å, b = 17.222(1) Å, c = 13.266(1) Å, β = 95.529(1)°, V = 2784.1(6) ų, Z = 2, with final residuals R = 0.0509 and Rw = 0.0582. Crystal data for 24CH₃Cl₂: space group P2₁/n, a = 13.438(1) Å, b = 19.276(1) Å, c = 14.182(1) Å, β = 111.464(1)°, V = 3418.9(6) ų, Z = 2, with final residuals R = 0.0492 and Rw = 0.0695. Crystal data for 3·4CH₂Cl₂: space group P2₁/n, a= 13.579(1) Å, b = 19.425(1) Å, c = 14.199(1) Å, β = 111.881(2)°, V = 3475.6(7) ų, Z = 2, with final residuals R = 0.0703 and Rw = 0.0851. Comparison of the structural data shows that the effect of the axial ligand on weakening the Mo-Mo bond strength is X^? > CH₃CN > BF₄^?. The T_m values are 121.7 °C for 2 , 111.1 °C for 3 and 91.5 °C for 5 , respectively.     

Synthesen und NMR‐Untersuchungen von Salzen mit den neuen Anionen [PtXn(CF3)6‐n]2— (n = 0 ‐ 5, X = F,OH, Cl,CN) und die Kristallstrukturanalyse von K2[(CF3)2F2Pt(μ‐OH)2PtF2(CF3)2]·2H2O

Syntheses and NMR Spectroscopic Ivestigations of Salts containing the Novel Anions [PtX_n(CF₃)_6‐n]^2— (n = 0 ‐ 5, X = F, OH, Cl, CN) and Crystal Structure of K₂[(CF₃)₂F₂Pt(μ‐OH)₂PtF₂(CF₃)₂]·2H₂O The first syntheses of trifluoromethyl‐complexes of platinum through fluorination of cyanoplatinates are reported. The fluorination of tetracyanoplatinates(II), K₂[Pt(CN)₄], and hexacyanoplatinates(IV), K₂[Pt(CN)₆], with ClF in anhydrous HF leads after working up of the products to K₂[(CF₃)₂F₂Pt(μ‐OH)₂PtF₂(CF₃)₂]·2H₂O. The structure of the salt is determined by a X‐ray structure analysis, P2₁/c (Nr. 14), a = 11.391(2), b = 11.565(2), c = 13.391(3)Å, β = 90.32(3)°, Z = 4, R₁ = 0.0326 (I > 2σ(I)). The reaction of [Bu₄N]₂[Pt(CN)₄] with ClF in CH₂Cl₂ generates mainly cis‐[Bu₄N]₂[PtCl₂(CF₃)₄] and fac‐[Bu₄N]₂[PtCl₃(CF₃)₃], but in contrast that of [Bu₄N]₂[Pt(CN)₆] with ClF in CH₂Cl₂ results cis‐[Bu₄N]₂[PtX₂(CF₃)₄], [Bu₄N]₂[PtX(CF₃)₅] (X = F, Cl) and [Bu₄N]₂[Pt(CF₃)₆]. In the products [Bu₄N]₂[PtX_n(CF₃)_6‐n] (X = F, Cl, n = 0—3) it is possibel to exchange the fluoro‐ligands into chloro‐ and cyano‐ligands by treatment with (CH₃)₃SiCl und (CH₃)₃SiCN at 50 °C. With continuing warming the trifluoromethyl‐ligands are exchanged by chloro‐ and cyano‐ligands, while as intermediates CF₂Cl and CF₂CN ligands are formed. The identity of the new trifluoromethyl‐platinates is proved by ¹⁹⁵Pt‐ and ¹⁹F‐NMR‐spectroscopy.     

Versatile and Efficient Synthesis of a New Class of Aza‐Based Phosphinic Amide Ligands via Unusual P?C Cleavage

A new class of bidentate, aza‐based phosphinic amide ligands of the type RN(H)P(?O)(2‐py)₂ (2‐py = 2‐pyridyl) was synthesized within minutes via a one‐pot process including Staudinger reaction of an organic azide (RN₃) with 2‐pyridylphosphines, followed by partial, unprecedented hydrolysis under loss of one aromatic substituent. The structure of the unusual‐hydrolysis product H₂C?CH(CH₂)₉N(H)P(?O)(2‐py)₂ ( 5a ) was characterized by IR, ¹H‐ and ³¹P‐NMR, as well as by X‐ray crystal‐structure analysis (Figure). The tetrahedral P‐atom was found to be surrounded by a trigonal‐pyramidal arrangement of the substituents. To gain insight into the formation of these novel phosphinic amides, a series of intermediate iminophosphoranes, H₂C?CH(CH₂)₉N?P(Ar)_n(2‐py)_{3 ? n} (n = 0–3), compounds 1a – 1f , were synthesized, and their hydrolyses were studied. All tested compounds followed the classical hydrolysis route of P?N cleavage under acidic conditions. Sequential hydrolysis to 5a – 5d only occurred under either basic conditions or in wet MeCN as solvent. Notably, H₂C?CH(CH₂)₉N?P(C₆H₅)(4‐MeO‐2‐py)₂ ( 1c ) was hydrolyzed at a much slower rate compared to its analogue 1b lacking the MeO group. On the contrary, the halogenated compounds H₂C?CH(CH₂)₉N?P(4‐X‐C₆H₄)₃ ( 1f,g ) (X = F, Cl) were hydrolyzed at a notably faster rate relative to the non‐halogenated congener 1e (X = H).     

Synthesis of sulphonated aminomethylphosphines and some nickel(II), palladium(II), platinum(II) and rhodium(I) complexes. Crystal structure of [Et3NH][(Ph2PCH2)2 N(CH2)2SO3]

Summary Aminoalkanesulphonic acids H₂N(CH₂) _n SO₃H, (n = 1, 2 or 3) react with phosphonium salts [R₂P(CH₂OH)₂]Cl (R = Ph or Cy, Cy = cyclohexyl) in the presence of Et₃N to give the sulphonated aminomethylphosphines [Et₃NH] [(R₂PCH₂)₂N(CH₂) _n SO₃] (R = Ph, n = 1, 2 or 3; R = Cy, n = 1). The single crystal X-ray structure of [Et₃NH] [(Ph₂PCH₂)₂N(CH₂)₂SO₃] has been determined. Some Ni^II, Pd^II, Pt^II and Rh^I complexes of the phosphines have been prepared.     

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,Kristallstrukturen, Schwingungsspektren und Normalkoordinatenanalyse von [PtX2ox]2−, X = Cl,Br

Synthesis, Crystal Structure, Vibrational Spectra, and Normal Coordinate Analysis of [PtX₂ox]²⁻, X = Cl, Br By treatment of [PtX₄]^2— (X = Cl, Br) with C₂O₄^2— (ox^2—) in water [PtCl₂ox]^2— and [PtBr₂ox]^2— are formed which have been isolated by ion exchange chromatography on diethylaminoethyl cellulose. The crystal structures of [(C₅H₅N)₂CH₂][PtCl₂ox]·2H₂O ( 1 ) (orthorhombic, space group Pbca, a = 18.451(1), b = 18.256(1), c = 19.913(1)Å, Z = 16) and [(C₅H₅N)₂CH₂][PtBr₂ox] ( 2 ) (monoclinic, space group P2₁/c, a = 7.249(1), b = 10.180(1), c = 21.376(1)Å, β = 93.415(9)°, Z = 4) reveal nearly planar complex anions with C_2v point symmetry. The bond lengths are Pt‐Cl = 2.286, Pt‐Br = 2.405 und Pt‐O = 2.016 ( 1 ) und 2.030Å ( 2 ). In the vibrational spectra the PtX stretching vibrations are observed at 335 and 336 ( 1 ) and 219 and 231 cm^—1 ( 2 ). The PtO stretching vibrations are coupled with internal modes of the oxalato ligands and appear in the range of 350 — 800 cm^—1. Using the molecular parameters of the X‐Ray determinations the IR and Raman spectra of the (n‐Bu₄N) salts are assigned by normal coordinate analysis. The valence force constants are f_d(PtCl) = 1.97, f_d(PtBr) = 1.78 and f_d(PtO) = 2.48 ( 1 ) and 2.38 mdyn/Å ( 2 ). Taking into account increments of the trans influence a good agreement between observed and calculated frequencies is achieved. The NMR shifts are δ(¹⁹⁵Pt) = 3603.9 ( 1 ) and 3318.1 ppm ( 2 ).