Schwingungsspektren und Kraftkonstanten der Übergangsreihen OP(N(CH3)2)3 – OP(CH3)3 und SP(N(CH3)2)3 – SP(CH3)3

Vibrational Spectra and Force Constants of the Series OP(N(CH₃)₂)₃ – OP(CH₃)₃ and SP(N(CH₃)₂)₃ – SP(CH₃)₃ The vibrational spectra (IR and Raman) of the compounds of the title series are recorded and assigned to the normal vibrations. By a simplified force field the valence force constants are calculated and discussed. The results are compared with those of the NMR spectroscopy.     

Schwingungsspektren und Kraftkonstanten der Übergangsreihen OP(OCH3)3?OPCl3 und SP(OCH3)3?SPCl3

The IR- and RAMAN -spectra are reported from OP(OCH₃)₂Cl, OP(OCH₃)Cl₂, SP(OCH₃)Cl, SP(OCH₃)Cl₂. The assignement to the fundamental vibration is given and all Valence-force-constants are calculated. With increasing number of chlorine atoms decrease f P? OCH₃ and f P? Cl. In the contrary, f O? P and f S? P increase. Here the influence of decreasing electro negativity is compensated by the change from an element of the first period of eight elements to an element of the second period.     

Schwingungsspektren und Kraftkonstanten von W(OCH3)6, Mo(OCH3)6 und [Sb(CH3)4][Sb(OCH3)6]

Vibrational Spectra and Force Constants of W(OCH₃)₆, Mo(OCH₃)₆, and [Sb(CH₃)₄][Sb(OCH₃)₆] The infrared and Raman spectra of the monomeric hexamethoxides of Tungsten and Molybdenum and of the ionic compound [Me₄Sb]⁺[Sb(OMe)₆]^? (prepared from [Sb(OMe)₅]₂ and Me₄SbOMe; Me = CH₃) are recorded and interpreted on the basis of C_3i symmetry. The force fields of W(OMe)₆ and [Sb(OMe)₆]^? are calculated using the same basis set of force constants. Both W? O- and Sb? O- stretching force constants are identical (2.56 N/cm), however the other parts of the valence force field are markedly different.     

Alternativ-Liganden. XXX [1] Neue Tripod-Liganden XM' (OCH2PMe2)n(CH2CH2PMe2)3−n (M' = Si; Ge; n = 0–3) für Käfigstrukturen

Alternative Ligands. XXX Novel Tripod Ligands XM' (OCH₂PMe₂)_n(CH₂CH₂PMe₂)_3?n (M' = Si, Ge; n = 0–3) for Cage Structures Attempts to prepare new tripod ligands XSi(OCH₂PMe₂)₃ [X = CF₃ ( 15 ), C₆F₅ ( 16 ), NMe₂ ( 17 ), Cl ( 18 ), F ( 19 ), H ( 20 ), OEt ( 21 ), OMe ( 22 )] prove to be unsuccessful in spite of using different pathways, because the groups X undergo following reactions giving insoluble solids (polyadducts) or form inseparable mixtures, e. g. (RO)_nSi(OCH₂PMe₂)_4?n (R = Me, Et). In many cases Si(OCH₂PMe₂)₄ ( 13 ) can be isolated from the reaction mixture. The syntheses of the ligands XSi(CH₂CH₂PMe₂)₃ [X = NMe₂ ( 6 ), Cl ( 7 ), F ( 8 ), OMe ( 9 ), Vi ( 12 )], Si(OCH₂PMe₂)₄ ( 13 ) und Me₃GeOCH₂PMe₂ ( 14 ) are successful. The compounds MeSi(OCH₂PMe₂)₂CH₂CH₂NMe₂ ( 10 ) and MeSi(OCH₂PMe₂)₂CH₂CH₂P(CF₃)₂ ( 11 ) with different donor groups are obtained in good yields. The preparative program includes the synthesis of the known representatives MeSi(OCH₂PMe₃)₃ ( 1 ), MeSi(OCH₂PMe₂)₂CH₂CH₂PMe₂ ( 2 ), MeSi(OCH₂PMe₂)(CH₂CH₂PMe₂)₂ ( 3 ), MeSi(CH₂CH₂PMe₂)₃ ( 4 ) and MeGe(OCH₂PMe₂)₃ ( 5 ). Important preparative steps are the substitution of M'Cl (M' = Si, Ge) by Me₂PCH₂O groups and the photochemically induced or base catalyzed addition of HNMe₂, HPMe₂ or HP(CF₃)₂ to SiVi functions. The novel compounds are characterized by analytical and spectroscopic (IR, NMR, MS) investigations.     

Kinetics of gas‐phase reactions of CH3OCH2CF3, CH3OCH3, CH3OCH2CH3, CH3CH2OCH2CH3, and CHF2CF2OCH2CF3 with NO3 radicals at 298 K

Rate constants for the gas‐phase reactions of CH₃OCH₂CF₃ (k₁), CH₃OCH₃ (k₂), CH₃OCH₂CH₃ (k₃), and CH₃CH₂OCH₂CH₃ (k₄) with NO₃ radicals were determined by means of a relative rate method at 298 K. NO₃ radicals were prepared by thermal decomposition of N₂O₅ in a 700–750 Torr N₂O₅/NO₂/NO₃/air gas mixture in a 1‐m³ temperature‐controlled chamber. The measured rate constants at 298 K were k₁ = (5.3 ± 0.9) × 10^?18, k₂ = (1.07 ± 0.10) × 10^?16, k₃ = (7.81 ± 0.36) × 10^?16, and k₄ = (2.80 ± 0.10) × 10^?15 cm³ molecule^?1 s^?1. Potential energy surfaces for the NO₃ radical reactions were computationally explored, and the rate constants of k₁–k₅ were calculated according to the transition state theory. The calculated values of rate constants k₁–k₄ were in reasonable agreement with the experimentally determined values. The calculated value of k₅ was compared with the estimate (k₅ < 5.3 × 10^?21 cm³ molecule^?1 s^?1) derived from the correlation between the rate constants for reactions with NO₃ radicals (k₁–k₄) and the corresponding rate constants for reactions with OH radicals. We estimated the tropospheric lifetimes of CH₃OCH₂CF₃ and CHF₂CF₂OCH₂CF₃ to be 240 and >2.4 × 10⁵ years, respectively, with respect to reaction with NO₃ radicals. The tropospheric lifetimes of these compounds are much shorter with respect to the OH reaction. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 41: 490–497, 2009     

Schwingungsspektren und Kraftkonstanten der Übergangsreihen OP(OCH3)3?OP(SCH3)3 und SP(OCH3)3?SP(SCH3)3

The IR- and RAMAN spectra are reported for the above mentionned compounds. All valence force-constants are calculated. The substitution of oxygen by sulfur causes a decrease of all force-constants. 18% for f P? OCH₃ and f P? SCH₃, 10% for f O?P and f S?P and 2% for f O? CH₃ and f S? CH₃.     

Alternativ-Liganden. XXXI. Nickelcarbonylkomplexe mit Tripod-Liganden des Typs XM′(OCH2PMe2)n(CH2CH2PR2)3–n (M′ = Si,Ge; n = 0–3)

Alternative Ligands. XXXI. Nickelcarbonyl Complexes of Tripod Ligands of the Type XM′(OCH₂PMe₂)_n(CH₂CH₂PR₂)_3–n (M′ = Si, Ge; n = 0–3) The coordinating properties of the tripod ligands RM′(OCH₂PMe₂)_n(CH₂CH₂PMe₂)_3–n (M′ = Si, Ge) ( 1–7 ), MeSi(OCH₂PMe₂)₂CH₂CH₂P(CF₃)₂ ( 8 ), MeSi(OCH₂PMe₂)₂CH₂CH₂NMe₂( 10 ) as well as of the tetradentate representative Si(OCH₂PMe₂)₄ ( 9 ) have been investigated by the preparation of the novel nickel carbonyl complexes LNiCO ( 11–18 ), Si(OCH₂PMe₂)₄[Ni(CO)₂]₂ ( 19 ) and (HOCH₂PMe₂)₂Ni(CO)₂ ( 20 ). They are obtained in moderate to good yields by the reaction of Ni(CO)₄ with the corresponding ligands in toluene (20–111°C) (see Table 1). The new compounds have been characterized by analytical (C, H) and spectroscopic investigations (IR; ¹H-, ¹³C-, ¹⁹F, ³¹P-NMR, MS). The ligand properties are discussed on the basis of spectroscopic data [in particular coordination shifts Δδ = δ(complex)—δ(ligand)] leading to the conclusion that the high electron density on Ni gives rise to a weak, but significant Ni→Si interaction. An important indication comes from the large low field shift Δδ_F = 34.5 ppm for the SiF acceptor bridge in 17 . This result is supported by an X-ray diffraction study of 11 giving an NiSi distance of 3.941(2) Å. With the exception of O2…?P3 (Abb. 7) all other O…?P through-cage contacts are longer than the NiSi distance. An additional release from the high charge density on Ni is obtained via π-backbonding to the neighbouring groups OCPMe₂, CCPMe₂ and CO.     

Synthesis and characterization of ferrocenylalkoxygermatranes and crystal structures of FcCH2OGe (OCH2CH2)3N and FcCH(CH3)OGe(OCH2CH2)3N1

Germatranes bearing a ferrocenylalkoxyl moiety have been obtained by the reaction of HOGe(OCH₂CH₂)₃N with various ferrocenyl alcohols. A convenient new synthesis method of FcCH₂OGe(OCH₂CH₂)₃N was reported. FcCH₂OGe(OCH₂CH₂)₃N was prepared in 93% yield when FcCH₂OH reacted with HOGe(OCH₂CH₂)₃N in chloroform at room temperature in the presence of molecular sieves (3 Å) as a dehydrating agent. All compounds were characterized by elemental analysis, ¹H NMR and IR spectroscopy. The molecular structures of FcCH₂OGe(OCH₂CH₂)₃N and FcCH(CH₃)OGe(OCH₂CH₂)₃N have been determined by X‐ray diffraction. The antitumor activities of FcCH₂OGe(OCH₂CH₂)₃N and p‐FcC₆H₄CH₂OGe(OCH₂CH₂)₃N were determined. Copyright © 2005 John Wiley & Sons, Ltd.     

(CH3)2SBr2 – einige Reaktionen und Strukturen

(CH₃)₂SBr₂ – Reactions and Structures (CH₃)₂SBr₂ ( 1 ) is a donor acceptor complex (8-S-3 + 10-Br-2) which reacts with (CH₃)₂S(?O)NSi(CH₃)₃ to yield [(CH₃)₂S(O)?N? S(CH₃)₂]⁺Br^? ( 2 ). With SbBr₃ (CH₃)₂SBr⁺SbBr₄^? ( 3 ) can be isolated. 1 crystallizes monoclinic in the space group P2₁/c with a = 733.8, b = 734.2, c = 1132.7 pm, β = 92.8° and Z = 4. 2 crystallizes in the orthorhombic space group Pnma with a = 967.2, b = 793.3, c = 1168.3 pm and Z = 4. The SBr and BrBr force constants of 1 are compared with those of S₂Br₂, 3 and Br₂ resp. The nmr and mass spectra of 1 and 2 are communicated.     

Darstellung und spektroskopische Charakterisierung der Persulfoniumsalze (CH3)(CF3)SF3+SbF6− und (CH3)(CF3)2SF2+SbF6− und Kristallstruktur von CF3SF2+SbF6−

Preparation and Spectroscopic Characterization of the Persulfonium Salts (CH₃)(CF₃)SF₃⁺SbF₆^? and (CH₃)(CF₃)₂SF₂⁺SbF₆^? and Crystal Structure of CF₃SF₂⁺SbF₆^? [1] . The preparation of the persulfonium salts (CH₃)(CF₃)SF₃⁺SbF₆^? and (CH₃)(CF₃)₂SF₂⁺SbF₆^? by methylation of the sulfuranes CF₃SF₃ and (CF₃)₂SF₂ with CH₃OSO⁺SbF₆^? in liquid SO₂ is reported. The thermolabile compounds are characterized by IR, Raman, ¹H, ¹³C, and ¹⁹F NMR spectroscopy. CF₃SF₂⁺SbF₆^? crystallizes in the space group C2/c with a=16.889(8) Å, b=7.261(4) Å, c=13.416(7) Å, β=91.08° with 8 formula units per unit cell at 167 K. Cations and anions are connected via short SF contacts forming a Ψ-octahedral surrounding of the central S atom which is in close analogy to the already known CF₃SF₂⁺AsF₆^?.     

Thermal decomposition of di-t-butyl peroxide in the presence of (CH3)2CCH2: Reactions of CH3, (CH3)2ĊCH2CH3, and (CH3)2ĊCH2C(CH3)2CH2CH3 radicals

A study of the reaction initiated by the thermal decomposition of di-t-butyl peroxide (DTBP) in the presence of (CH₃)₂C?CH₂ (B) at 391–444 K has yielded kinetic data on a number of reactions involving CH₃ (M·), (CH₃)₂CCH₂CH₃ (MB·) and (CH₃)₂?CH₂C(CH₃)₂CH₂CH₃ (MBB·) radicals. The cross-combination ratio for M· and MB· radicals, rate constants for the addition to B of M· and MB· radicals relative to those for their recombination reactions, and rate constants for the decomposition of DTBP, have been determined. The values are, respectively, where θ = RT ln 10 and the units are dm^3/2 mol^?1/2 s^?1/2 for k₂/k and k₉/k, s^?1 for k₀, and kJ mol^?1 for E. Various disproportionation-combination ratios involving M·, MB·, and MBB· radicals have been evaluated. The values obtained are: Δ₁(M·, MB·) = 0.79 ± 0.35, Δ₁(MB·, MB·) = 3.0 ± 1.0, Δ₁(MBB·, MB·) = 0.7 ± 0.4, Δ₁(M·, MBB·) = 4.1 ± 1.0, Δ₁(MB·, MBB·) = 6.2 ± 1.4, and Δ₁(MBB·, MBB·) = 3.9 ± 2.3, where Δ₁ refers to H-abstraction from the CH₃ group adjacent to the center of the second radical, yielding a 1-olefin. © 1994 John Wiley & Sons, Inc.     

Analysis of the intermolecular interaction between CH(3)OCH(3), CF(3)OCH(3), CF(3)OCF(3), and CH(4): high level ab initio calculations

The intermolecular interaction energies of the CH₃OCH₃? CH₄, CF₃OCH₃? CH₄, and CF₃OCF₃? CH₄ systems were calculated by ab initio molecular orbital method with the electron correlation correction at the second order Møller–Plesset perturbation (MP2) method. The interaction energies of 10 orientations of complexes were calculated for each system. The largest interaction energies calculated for the three systems are ?1.06, ?0.70, and ?0.80 kcal/mol, respectively. The inclusion of electron correlation increases the attraction significantly. It gains the attraction ?1.47, ?1.19, and ?1.27 kcal/mol, respectively. The dispersion interaction is found to be the major source of the attraction in these systems. In the CH₃OCH₃? CH₄ system, the electrostatic interaction (?0.34 kcal/mol) increases the attraction substantially, while the electrostatic energies in the other systems are not large. Fluorine substitution of the ether decreases the electrostatic interaction, and therefore, decreases the attraction. In addition the orientation dependence of the interaction energy is decreased by the substitution. © 2002 Wiley Periodicals, Inc. J Comput Chem 23: 1472–1479, 2002     

Kinetics for the gas‐phase reactions of OH radicals with the hydrofluoroethers CH2FCF2OCHF2, CHF2CF2OCH2CF3, CF3CHFCF2OCH2CF3, and CF3CHFCF2OCH2CF2CHF2 at 268–308 K

Rate constants were determined for the reactions of OH radicals with the hydrofluoroethers (HFEs) CH₂FCF₂OCHF₂(k₁), CHF₂CF₂OCH₂CF₃ (k₂), CF₃CHFCF₂OCH₂CF₃(k₃), and CF₃CHFCF₂OCH₂CF₂CHF₂(k₄) by using a relative rate method. OH radicals were prepared by photolysis of ozone at UV wavelengths (>260 nm) in 100 Torr of a HFE–reference–H₂O–O₃–O₂–He gas mixture in a 1‐m³ temperature‐controlled chamber. By using CH₄, CH₃CCl₃, CHF₂Cl, and CF₃CF₂CF₂OCH₃ as the reference compounds, reaction rate constants of OH radicals of k₁ = (1.68) × 10^?12 exp[(?1710 ± 140)/T], k₂ = (1.36) × 10^?12 exp[(?1470 ± 90)/T], k₃ = (1.67) × 10^?12 exp[(?1560 ± 140)/T], and k₄ = (2.39) × 10^?12 exp[(?1560 ± 110)/T] cm³ molecule^?1 s^?1 were obtained at 268–308 K. The errors reported are ± 2 SD, and represent precision only. We estimate that the potential systematic errors associated with uncertainties in the reference rate constants add a further 10% uncertainty to the values of k₁–k₄. The results are discussed in relation to the predictions of Atkinson's structure–activity relationship model. The dominant tropospheric loss process for the HFEs studied here is considered to be by the reaction with the OH radicals, with atmospheric lifetimes of 11.5, 5.9, 6.7, and 4.7 years calculated for CH₂FCF₂OCHF₂, CHF₂CF₂OCH₂CF₃, CF₃CHFCF₂OCH₂CF₃, and CF₃CHFCF₂OCH₂CF₂CHF₂, respectively, by scaling from the lifetime of CH₃CCl₃. © 2003 Wiley Periodicals, Inc. Int J Chem Kinet 35: 239–245, 2003     

Alternativ-Liganden. XXXII [1]. Neue Tetraphosphan-Nickelkomplexe mit Tripod-Liganden des Typs XM′ (OCH2PMe2)n(CH2CH2PR2)3 – n (M′ = Si,Ge; n = 0 – 3)

Alternative Ligands. XXXII [1]. Novel Tetraphosphane Nickel Complexes with Tripod-Ligands of the Type XM′(OCH₂PMe₂)_n(CH₂CH₂PR₂)_{3 – n} (M′ = Si, Ge; n = 0 – 3) Tripod Ligands of the type XM′(OCH₂PMe₂)_n(CH₂CH₂PMe_{23 – n} (M′ = Si, Ge; n = 0 – 3) ( 1 – 6 , Table 1) have been used together with PPh₃ or PMe₃ for the preparation of novel tetraphosphane complexes of Nickel. The representatives LNiPPh₃ ( 7 – 12 ) are obtained by reaction of Ni(COD)₂ (COD = 1,5-cyclooctadiene) with the corresponding ligands and PPh₃ in toluene in moderate yields. The synthesis of the derivatives LNiPMe₃ ( 13 – 18 ) is partly ( 16 – 18 ) accomplished in analogy to the Ph₃P-complexes; compounds 13 – 16 are obtained in higher yields by reaction of Ni(PMe₃)₄ with the respective ligand. As a rule, 13 – 18 cannot be separated from by-products. The trinuclear complex FSi(CH₂CH₂PMe₂)₃[Ni(PMe₂CH₂CH₂)₃SiF]₃ ( 19 ) is formed together with 18 in the reaction of Ni(COD)₂ with 6 and PMe₃. The new compounds have been characterized (if possible) by analytical (C, H), but in general by spectroscopic investigations (IR; ¹H-, ¹³C-, ¹⁹F-, ³¹P-NMR; MS). A weak, but significant Ni → Si interaction through the cage is indicated by the following results: (i) Large low-field shifts δδ_F of 35.2 ppm ( 12 ), 38.3 ppm ( 18 ) and 37.7 ppm ( 19 ); (ii) ⁶J(PF) coupling constants [or ³J(PNiSiF) through the cage] of 6.0 Hz ( 12 ) and 7.6 Hz ( 18 ) together with a low-field shift δδ_Si of 12.8 ppm ( 12 ); (iii) NiSi distances of 3.95 Å in 7 and 3.92 Å in 12 , accompanied by a compression of the cage along the Ni ··· Si axis. An additional release from the high charge density on Ni results from π-backbonding to the phosphane ligands.     

Reaktionsprodukte aus Chlormethoxiphosphinen und Antimon(V)-chlorid. Schwingungsspektren der 1:1 Addukte aus Methoxiphosphorylverbindungen und Antimon(V)-chlorid

Reaction Products of Chloromethoxiphosphines and Antimony (V) Chloride. Vibrational Spectra of the 1:1-adducts of Methoxiphosphoryl Compounds and Antimony (V) Chloride Chloromethoxiphosphines react with antimony(V) chloride in a redox process to yield the chloromethoxiphospllonium hexachloroantimonates(V) (CH₃O)₃PCl₂⁺SbCl₆^? (II) and CH₃OPCl₃⁺SbCl₆^? (III). II, III, (CH₃O)₃PCl⁺SbCl₆^?(1) and (CH₃O)₄P⁺SbCl₆^? eliminate easily methyl chloride and give the addition compounds OP(OCH₃)₃·SbCl₅(IV), OPCl(OCH₃)₂ · SbCl₅ (V), OPCl₂(OCH₃)·SbCl₅ (VI) and OPCl₃·SbCl₅ (VII). The vibrational spectra of IV, V nnd VI are discussed.     

Attempted Abstraction of the Halogenides in (HNEt3)[Re(CH3CN)2Cl4] and Crystal Structures of cis‐[Re(CH3CN)2Cl4]·CH3CN and cis‐[Re(NHC(OCH3)CH3)2Cl4]

The abstraction of the halogenide ligands in [Re(CH₃CN)₂Cl₄]^? should result in a solvent‐only stabilized Re^III complex. The reactions of salts of [Re(CH₃CN)₂Cl₄]^? with silver(I) and thallium(I) salts were investigated and the solid‐state structures of cis‐[Re(CH₃CN)₂Cl₄]·CH₃CN and cis‐[Re(NHC(OCH₃)CH₃)₂Cl₄] are described.     

Arynic Condensation of Nitrile Anions in the Presence of the Complex Base NaNH2-CH3CH2(OCH2CH2)2ONa

Nitrite anions are easily condensed with aryl halides in the presence of the Complex Base NaNH₂-CH₃CH₂(OCH₂CH₂)₂ONa via the intermediate arynes.     

Atran-analoge Verbindungen III. Atran-analoge Verbindungen des Typs Me2DCH2CH2OSi(Me) (OCH2CH2)2D′ Me (I) und Me2DCH2CH2OSi(Me) (OCH2CH2D′Me2)OCH2CH2D″ Me2 (II) (MeCH3; D,D′, D‴N,P, As)

Atrane-analogous Compounds. III. Atrane-analogous Compounds of the Type Me₂DCH₂CH₂OSi(Me)(OCH₂ CH₂)₂ D′Me (I) and Type Me₂DCH₂CH₂OSi(Me) OCH₂CH₂₂D″Me₂ (II) (Me?CH₃; D, D′, D″?N, P, As) Atrane analogous compounds I and II (Abb. 1) have been prepared by condensation reactions of trifunctional silanes RSiX₃ (X?Cl, OEt, NMe₂) with N-methyldiethanolamine, ß-chloroethanol, ß-dimethylaminoethanol, and ß-dimethylarsanoethanol according to eqn. (1) to (3) and reaction schemes of Figs. 2 and 3, respectively. For compounds of type I weak N→Si adduct bonding is indicated for the MeN-donor of the eight-membered ring by significant shifts of the MeNCH₂ and OCH₂ proton n.m.r. signals. For compounds of type II there is no n.m.r. evidence for D→Si interactions. In spite of equal Lewis acidity of the Si atoms differences in adduct formation are observed for cage, ring, and acyclic podand systems, which can be explained mainly by entropy effects connected to the formation of five-membered rings.     

Syntheses and Structures of S4N4(OCH3)2 and CH3OS4N4(O)Cl

The reaction of S₄N₄Cl₂ with CH₃OH gives S₄N₄(OCH₃)₂, a simple dimethoxoderivative of S₄N₄. Its overall geometry is analogous to other compounds of the S₄N₄X₂ type. The chlorination of S₄N₄(OCH₃)₂ leads to the oxidation of one sulfur atom to S^VI and CH₃OS₄N₄(O)Cl is formed. The compounds were characterized by ir spectroscopy and their crystal structures were determined from single crystal diffraction data collected at ?153°C. The presence of S^VI in the molecule of CH₃OS₄N₄(O)Cl is manifested by a marked shortening of the bonds formed by this atom as compared with S₄N₄Cl₂ and S₄N₄(OCH₃)₂.     

Kernresonanzspektroskopische Untersuchungen an cis-(CH3)2Pt[P(OCH3)3]2

100 MHz ¹ H n.m.r. spectra of cis-(CH₃)₂Pt[P(OCH₃)₃]₂ are analysed in full detail as superimposing [AR₃X₉]₂ and [AR₃X₉]₂M systems. The cis structure is derived from J(PP) and J(PtP).