Spectroscopic calculations for the (CH3)3N · BF3 and (CH3)3N · BCL3 complexes

Mean amplitudes of vibration and perpendicular amplitude correction coefficients are calculated for (CH₃)₃N · BF₃ and (CH₃)₃N · BCl₃ complexes using different versions of force fields originating from spectroscopic studies with somewhat different assignments. The results are discussed in conjunction with the electron diffraction results and bonding features.     

Phosphanimin- und Phosphaniminato-Komplexe von Bor. Synthese und Kristallstrukturen von [BF3(Me3SiNPEt3)], [BCl2(NPPh3)]2, [BCl2(NPEt3)]2, [B2Cl3(NPEt3)2]+BCl4− und [B2Cl2(NPiPr3)3]+BCl4−

Phosphaneimine and Phosphoraneiminato Complexes of Boron. Synthesis and Crystal Structures of [BF₃(Me₃SiNPEt₃)], [BCl₂(NPPh₃)]₂, [BCl₂(NPEt₃)]₂, [B₂Cl₃(NPEt₃)₂]⁺BCl₄^?, and [B₂Cl₂(NPⁱPr₃)₃]⁺BCl₄^? The title compounds have been prepared from the corresponding silylated phosphaneimines and boron trifluoride etherate and boron trichloride, respectively. The compounds form white moisture sensitive crystals, which were characterized by ¹¹B-nmr-spectroscopy, IR-spectroscopy and by crystal structure determinations. [BF₃(Me₃SiNPEt₃)] : Space group P2₁/c, Z = 4, R = 0.032 for reflections with I > 2σ(I). Lattice dimensions at ?70°C: a = 1361.0, b = 819.56, c = 1422.5 pm, β = 109.86°. The donor acceptor complex forms monomeric molecules with a B? N bond length of 157.8 pm. [BCl₂(NPPh₃)]₂ · 2 CH₂Cl₂ : Space group P2₁/c, Z = 2, R = 0.049 for reflections with I > 2σ(I). Lattice dimensions at ?50°C: a = 1184.6, b = 2086.4, c = 843.0 pm, β = 96.86°. The compound forms centrosymmetric dimeric molecules in which the boron atoms are linked to B₂N₂ four-membered rings with B? N distances of 152.7 pm via μ₂-N bridges of the NPPh₃ groups. [BCl₂(NPEt₃)]₂ : Space group Pbca, Z = 4, R = 0.029 for reflections with I > 2σ(I). Lattice dimensions at ?90°C: a = 1269.5, b = 1138.7, c = 1470.3 pm. The compound has a molecular structure corresponding to the phenyl compound with B? N ring distances of 151.0 pm. [B₂Cl₃(NPEt₃)₂]⁺BCl₄^? : Space group Pbca, Z = 8, R = 0.034 for reflections with I > 2σ(I). Lattice dimensions at ?70°C: a = 1309.3, b = 1619.8, c = 2410.7 pm. Within the cations the boron atoms are linked to planar, asymmetrical B₂N₂ four-membered rings with B? N distances of 155.1 and 143.1 pm via the μ₂-N atoms of the NPEt₃ groups. [B₂Cl₂(NPⁱPr₃)₃]⁺BCl₄^? · CH₂Cl₂: Space group Pna2, Z = 4, R = 0.033 for reflections with I > 2σ(I). Lattice dimensions at ?70°C: a = 1976.5, b = 860.2, c = 2612.7 pm. Within the cations the boron atoms are linked to planar, asymmetrical B₂N₂ four-membered rings with B? N distances of 153.7 and 150.5 pm via the μ₂-N atoms of two of the NPⁱPr₃ groups. The third NPⁱPr₃ group is terminally connected to the sp²-hybridized boron atom with a B? N distance of 133.5 pm and with a B? N? P bond angle of 165.3°.     

A Tri-Coordinate-Magnesium Silylamide Complex: {[(CH3)3Si]2N}2MgO(CH2CH2)2OMg{N[Si(CH3)3]2}2

The reaction of diethylmagnesium dioxane adduct solution with 1,1,1,3,3,3-hexamethyldisilazan ((CH₃)₃SiNHSi(CH₃)₃) gives {[(CH₃)₃Si]₂N}₂MgO(CH₂CH₂)₂OMg{N[Si(CH₃)₃]₂}₂ (1); this alkoxomagnesium silylamide in the solid state contains unprecedented three-coordinate magnesium and oxygen atoms.     

Synthesis,Crystal Structure,and Spectroscopic Characterization of the Borazine Derivatives [B{CH2(SiCl3)}NH]3 and [B{CH2(SiCl2CH3)}NH]3

The borazine derivatives B, B′, B″‐tris[(trichlorosilyl)methyl]borazine [B{CH₂(SiCl₃)}NH]₃ ( 1 ), and B, B′, B″‐tris[{dichloro(methyl)silyl}methyl]borazine [B{CH₂(SiCl₂CH₃)}NH]₃ ( 2 ) were prepared by reacting (Cl₃Si)CH₂(BCl₂) ( 3 ) and [Cl₂(CH₃)Si]CH₂(BCl₂) ( 4 ) with hexamethyldisilazane (hmds), respectively. Both compounds, 1 and 2 crystallize in space group R3c with a = 1712.53(4), c = 1230.33(4) pm, Z = 6, R₁ = 0.030, and a = 1713.8(2), c = 1258.7(2) pm, Z = 6, R₁ = 0.034, respectively. According to the single crystal X‐ray diffraction analyses, the title compounds show a planar B₃N₃ six‐membered ring with B—N distances of 142.3(3) pm (point symmetry C₃) and synfacial oriented substituents. The borazine derivatives have also been characterized by NMR and IR spectroscopy as well as by MS spectrometry.     

Kombination von Ionenaustausch und Gefriertrocknung als Syntheseweg zu neuen Oxoferraten(VI) M2FeO4 mit M = Li,Na, N(CH3)4, N(CH3)3Bzl,N(CH3)3Ph

Combination of Ion Exchange and Freeze Drying as a Synthetic Route to New Oxoferrates(VI) M₂FeO₄ with M = Li, Na, N(CH₃)₄, N(CH₃)₃Bzl, N(CH₃)₃Ph For the first time Oxoferrates(VI) M₂FeO₄ with M = Li, Na, N(CH₃)₄, N(CH₃)₃Bzl and N(CH₃)₃Ph have been prepared by cation exchange reaction on K₂FeO₄ and freeze drying of the resulting aqueous solutions. Li₂FeO₄ crystallizes as a monohydrate and decomposes at –10 ± 3 °C. Na₂FeO₄ crystallizes orthorhombically (Cmcm, a = 5.675(3) Å, b = 9.349(4) Å, c = 7.160(2) Å) and is isostructural to Na₂CrO₄. [N(CH₃)₄]₂FeO₄ crystallizes tetragonally (P4/nbm, a = 11.010(3) Å, c = 10.902(4) Å) and is isostructural to the room temperature modification of [N(CH₃)₄]₂SO₄. Infrared spectra of the alkylammonium ferrates(VI) show a decreasing influence of lattice forces on the vibrations of the FeO₄^2– ions with increasing cation size. Magnetic measurements show the expected paramagnetism for a d² ion.     

Zur solvensfreien Darstellung von Tetramethylammoniumsalzen: Synthese und Charakterisierung von [N(CH3)4]2[C2O4], [N(CH3)4][CO3(CH3)], [N(CH3)4][NO2], [N(CH3)4][CO2H] und [N(CH3)4][O2C(CH2)2CO2(CH3)]

Solvent-free Synthesis of Tetramethylammonium Salts: Synthesis and Characterization of [N(CH₃)₄]₂[C₂O₄], [N(CH₃)₄][CO₃CH₃], [N(CH₃)₄][NO₂], [N(CH₃)₄][CO₂H], and [N(CH₃)₄][O₂C(CH₂)₂CO₂CH₃] A general procedure to synthesize tetramethylammonium salts is presented. Several tetramethylammonium salts were prepared in a crystalline state by solvent-free reaction of trimethylamine and different methyl compounds at mild conditions: [N(CH₃)₄]₂[C₂O₄] (cubic; a = 1 114.8(3) pm), [N(CH₃)₄][CO₃CH₃] (P2₁/n; a = 813.64(3), b = 953.36(3), c = 1 131.3(4) pm, β = 90.03(1)°), [N(CH₃)₄][NO₂] (Pmmn; a = 821.2(4), b = 746.5(3), c = 551.5(2) pm), [N(CH₃)₄][CO₂H] (Pmmn; a = 792.8(7), b = 791.7(3), c = 563.3(4) pm) and [N(CH₃)₄][O₂C(CH₂)₂CO₂CH₃] (P2₁; a = 731.1(2), b = 826.4(3), c = 1 025.2(3) pm, β = 110.1(1)°). The tetramethylammonium salts were characterized by IR-spectroscopy and X-ray diffraction. The crystal structures of the methylcarbonate and the nitrite are described.     

Darstellung,Kristallstruktur und spektroskopische Charakterisierung von [(H3C)3Si]NH(BCl2)

Preparation, Crystal Structure, and Spectroscopic Characterization of [(H₃C)₃Si]NH(BCl₂) [(H₃C)₃Si]NH(BCl₂) is formed during the reaction of boron trichloride with hexamethyldisilazane at low temperatures. The compound crystallizes monoclinic in space group P2₁/c with a = 953.8(2) pm, b = 1059.9(1) pm, c = 867.4(1) pm, β = 99.40(2)°; Z = 4. According to the single crystal X-ray diffraction analysis (1275 symmetry independent reflections, R = 0.040), [(H₃C)₃Si]NH(BCl₂) exists as a dimer, in the crystal. The dimers have site symmetry C_i and, within the margins of error of the structure determination, point symmetry C_2h. A characteristic feature is a planar, almost square B–N–B–N four-membered ring with the trimethylsilyl groups in trans position. The compound has been characterised by MS-, ¹H-, ¹³C-, ¹¹B-, and ²⁹Si-NMR-spectroscopy.     

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.     

Die Kristall- und Molekularstruktur von Bordichloridazid (BCl2N3)3

Boron dichloride azide, (BCl₂N₃)₃, crystallizes in the monoclinic space group P21/c with 4 formula units per unit cell; the lattice parameters are a = 8.874, b = 14.494, c = 10.538 Å and β = 99.7°. The crystal structure was solved by direct determination of the signs of 76 structure factors and a following Fourier synthesis and was refined by the method of least squares to R = 5.8% for the 793 observed reflexions. The structure is built up from (BCl₂N₃)₃ molecules which are arranged in a way that resembles a face centered lattice. The (BN)₃ ring of the molecule has a skew boat conformation with the approximate point symmetry 2. Each boron atom is co-ordinated by two Cl and two N atoms in a distorted tetrahedral arrangement. New aspects concerning the assignment of the vibrational spectrum are discussed.     

Synthese und strukturelle Studien von Aluminiumdialkylaminen und ‐amiden: N‐Chiralität von (CH3)3AlNHRR′ und cis‐trans‐Isomerie an X2AlNRR′ (X = CH3, Cl,H)

Synthesis and Structural Studies of Aluminum Dialkylamines and Dialkylamides: N‐Chirality of (CH₃)₃AlNHRR′ and cis‐trans ‐Isomerism at X₂AlNRR′ (X = CH₃, Cl, H) Aluminum dialkylamines and dialkylamides were prepared from Al(CH₃)₃ and NH(CH₃)R′ (R′: –C₂H₅, –^tC₄H₉) and characterized by elemental analyses, ¹H‐, ¹³C‐, and ²⁷Al‐NMR spectroscopy. The crystal structures of [(CH₃)₂AlN(CH₃)(–^tC₄H₉)]₂ ( IV ), [Cl₂AlN(CH₃)(C₂H₅)]₂ ( V ), and [H₂AlN(CH₃)(C₂H₅)]_∞ ( VI‐trans and VI‐cis ) are discussed.     

EPR of gamma irradiated (CH3)3NHClO4, (CH3)3NHBF4 and [(CH3)4N]2ZnCl4 single crystals

Gamma irradiation damage centres in (CH₃)₃NHClO₄, (CH₃)₃NHBF₄ and [(CH₃)₄N]₂ZnCl₄ were investigated by electron paramagnetic resonance spectroscopy at room temperature. The centres were found to be (CH₃)₃N^+. and the hyperfine structure parameters for methyl protons and the nitrogen nucleus were determined. The results indicated that the (CH₃)₃N^+. radical wholly performs reorientational motions around its C_3v axis in addition to the reorientatonal motions of the methyl groups around their C_3v axes. These results were compared with the earlier studies on (CH₃)₃N^+. radical and discussed. Low temperature measurements on the first two of the title compounds were assessed.     

Dimethyl-N-Halogenamine,ihre Ammoniumsalze und Bortrihalogenid-Addukte

Dimethyl-N-Halogenoamine, their Ammonium Salts and Borontrihalide Adducts The preparation and vibrational spectra of (CH₃)₂NHCl⁺X^? (X^? = CF₃SO₃^? I , SO₃F^? II , SO₃Cl^? III , BCl₄^? IV ), and (CH₃)₂NHBr⁺CF₃SO₃^? V as well as the adducts (CH₃)₂NCl · S (S = BF₃ VI , BCl₃ VII , BBr₃ VIII ) and (CH₃)₂NBr · BF₃ IX are reported. The crystal structure of VII has been determined from three-dimensional diffractometer data at ?100°C. The Cl atom and one methyl group in the dimethyl-N-chloroamino group show disorder. The structural data are: B? Cl 183(2) pm, B? N 167(3) pm, N? C 152(3) pm (distances to disordered positions are not included).     

Protonation of CH3N3 and CF3N3 in Superacids: Isolation and Structural Characterization of Long‐Lived Methyl‐ and Trifluoromethylamino Diazonium Ions

The methylamino diazonium cations [CH₃N(H)N₂]⁺ and [CF₃N(H)N₂]⁺ were prepared as their low‐temperature stable [AsF₆]^? salts by protonation of azidomethane and azidotrifluoromethane in superacidic systems. They were characterized by NMR and Raman spectroscopy. Unequivocal proof of the protonation site was obtained by the crystal structures of both salts, confirming the formation of alkylamino diazonium ions. The Lewis adducts CH₃N₃?AsF₅ and CF₃N₃?AsF₅ were also prepared and characterized by low‐temperature NMR and Raman spectroscopy, and also by X‐ray structure determination for CH₃N₃?AsF₅. Electronic structure calculations were performed to provide additional insights. Attempted electrophilic amination of aromatics such as benzene and toluene with methyl‐ and trifluoromethylamino diazonium ions were unsuccessful.     

Gold-Stickstoff-Heterocyclen. Synthese,Eigenschaften und Struktur von [(CH3)2AuNH2]4 und [(CH3)2AuN(CH3)2]2

Gold Nitrogen Heterocycles. Synthesis, Properties, and Structure of [(CH₃)₂AuNH₂]₄ and [(CH₃)₂AuN(CH₃)₂]₂ Dimethyl gold iodide reacts with alkali metal amides to form Au-N heterocycles. KNH₂ yields the eight-membered ring [(CH₃)₂AuNH₂]₄, whereas with LiN(CH₃)₂ the four-membered ring [(CH₃)₂AuN(CH₃)₂]₂ is obtained. The light sensitive, cyclic gold amides are stable against hydrolysis and do not react with Lewis bases. [(CH₃)₂AuN(CH₃)₂]₂ crystallizes monoclinic in the space group P2₁/c with Z = 2. The molecules exhibit the symmetry D_2h. Symmetrical amido bridges form a planar Au-N heterocyclus with distances Au-N = 214 pm.     

Optically active organoaluminum based inclusion compounds. Synthesis and characterization of (S)-(−)-α-[(C6H5)CH(CH3)N(CH3)3][Al2R6I] (R=CH3, C2H5)

The optically active quaternary ammonium salt (S)-(?)-α-[(C₆H₅)CH(CH₃)N(CH₃)₃I] reacts with AlR₃ to afford optically active organoaluminum based inclusion compounds, liquid clathrates, of the formula (S)-(?)-α-[(C₆H₅)CH(CH₃)N(CH₃)₃][Al₂R₆I] (R=CH₃, C₂H₅). Specific rotation ([α] ₂₅ ^D ) for the Al(CH₃)₃ compound was determined to be ?13.19° while that for the Al(C₂H₅)₃ analog was determined to be ?14.30°. There are 13.8 toluene molecules per anionic moiety for the trimethylaluminum based liquid clathrate while there are 15.0 toluene molecules per anion for the corresponding triethylaluminum inclusion compound.     

Über die Reaktion von Phosphorpentachlorid mit den BF3-Addukten primärer Amine

Reaction of CH₃NH₂ · BF₃ and PCl₅ yields CH₃N(PCl₃)(BCl₃), (I), the behaviour of which to PCl₅, pyridine and H₂S is described. By using smaller amounts of PCl₅, CH₃N(PCl₃)(BCl₂F) (VI) is obtained. C₆H₅NH₂ · BF₃ reacts with PCl₅ to give C₆H₅N(PCl₃)(BCl₃) (IX). Physical data, especially the NMR spectra of the new compounds, are given and discussed.     

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.     

Das Schwingungsspektrum des Ti[N(CH3)2]4

Zusammenfassung Die Infrarot- und Ramanspektren von Ti[N(CH₃)₂]₄ werden mitgeteilt, zugeordnet und mit den Spektren der analogen Dimethylamino-Verbindungen von Si, Ge und Sn verglichen.

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The IR and Raman spectra of Ti[N(CH₃)₂]₄ are reported, assigned and compared with those of the Si, Ge and Sn analoga.

     

Synthesis,Characterization, and Crystal Structures of [N(CH3)4]2[B12H12] and [N(CH3)4]2[B12H12] · CH3CN

Bis(tetramethylammonium) dodecahydrododecaborate, [(CH₃)₄N]₂[B₁₂H₁₂], and bis(tetramethylammonium) dodecahydrododecaborate acetonitrile, [(CH₃)₄N]₂[B₁₂H₁₂] · CH₃CN, were synthesized and characterized via Infrared, ¹H and ¹¹B NMR spectroscopy. [(CH₃)₄N]₂[B₁₂H₁₂] crystallizes isopunctual to the alkali metal dodecaborates. The crystal structure of [(CH₃)₄N]₂[B₁₂H₁₂] · CH₃CN was determined from single crystal data and refined in the orthorhombic crystal system (Pcmn, no. 62, a = 898.68(8), b = 1312.85(9) c = 1994.5(1) pm, R(|F| , 4σ) = 5.9%, wR(F²) = 18.3%). Here, the geometry of the dodecaborate anion is that of an almost ideal icosahedron, less distorted than most other dodecaborates known. By low‐temperature Guinier‐Simon diffractometry phase transitions were detected for [(CH₃)₄N]₂[B₁₂H₁₂] and [(CH₃)₄N]₂[B₁₂H₁₂] · CH₃CN at –70 and –15 °C, respectively.