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1.
Novel tricontinuous membranes consisting of well‐defined hydrophilic poly(ethylene glycol) (PEG) and lipophilic polyisobutylene (PIB) segments crosslinked by oxyphilic poly(pentamethylcyclopentasiloxane) (PD 5) domains have been synthesized and characterized. Tricontinuity arises because the three membrane constituents—PEG, PIB, and PD 5—are mutually incompatible and give rise to three independent cocontinuous phases (channels). The continuous PEG segments impart swelling in water (hydrogel character), the rubbery PIB moieties provide strength, and the PD 5 domains provide crosslinking and enhanced O 2 permeability. The synthesis involves the random cohydrosilation of various lengths (number‐average molecular weights) of α,ω‐diallyl‐PEG and α,ω‐diallyl‐PIB segments by pentamethylcyclopentasiloxane (D 5H) followed by water‐mediated oxidation of the SiH groups of the D 5H to SiOH groups, which immediately polycondense to PD 5 domains. Membranes containing about equal amounts of PEG, PIB, and PD 5 give rise to tricontinuous morphologies that allow the simultaneous permeation of water, heptane, and oxygen via three cocontinuous channels. The number‐average molecular weight of the PEG segment, that is, the number‐average molecular weight of the hydrophilic segment between two PD 5 crosslink sites, determines the dimensions (pore sizes) of the channels through which water can permeate. A method has been developed for studying the oxygen permeability of membranes. The microarchitecture of the membranes has been investigated with selective swelling experiments and Fourier transform infrared spectroscopy, their mechanical properties have been examined in the water‐swollen state with Instron measurements, and their bulk morphologies and thermal degradation have been determined with differential scanning calorimetry and thermogravimetric analysis, respectively. The findings have been interpreted in terms of phase‐separated PEG, PIB, and PD 5 microdomains. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1209–1217, 2002 相似文献
2.
From the reactions between 1,4-dilithiobutane and 1,2-M 2Cl 2(NMe 2) 4 compounds in hydrocarbon solvents, the 1,2-dimetallacyclo-1,2-hexyne compounds M 2(CH 2) 4(NMe 2) 4(MM), where M = Mo and W, have been obtained as yellow—orange, volatile microcrystalline compounds. Spectroscopic data are consistent with expectations based on previous studies of gauche 1,2-M 2R 2(NMe 2) 4 compounds in solution and a structural model based on the observed molecular structure of 1,2-Mo 2Et 2(NMe 2) 4 is presented and compared with the observed molecular structure of Mo 2(CH 2) 4(NMe 2) 4 found in the solid state. Pertinent bond distances (Å) and angles (°) are: Mo—Mo = 2.200(1), Mo—N = 1.96(1) (averaged), Mo—C = 2.165(8) (averaged), Mo—Mo—N = 105(1), Mo—Mo—C = 97(1). 相似文献
3.
Synthesis and Characterization of 2‐ O‐Functionalized Ethylrhodoximes and ‐cobaloximes 2‐Hydroxyethylrhodoxime and ‐cobaloxime complexes L—[M]—CH 2CH 2OH (M = Rh, L = PPh 3, 1 ; M = Co, L = py, 2 ; abbr.: L—[M] = [M(dmgH) 2L] (dmgH 2 = dimethylglyoxime, L = axial base) were obtained by reaction of L—[M] — (prepared by reduction of L—[M]—Cl with NaBH 4 in methanolic KOH) with BrCH 2CH 2OH. H 2O—[Rh] —, prepared by reduction of H[RhCl 2(dmgH) 2] with NaBH 4 in methanolic KOH, reacted with BrCH 2CH 2OH followed by addition of pyridine yielding py—[Rh]—CH 2CH 2OH ( 3 ). Complexes 1 and 3 were found to react with (Me 3Si) 2NH forming 2‐(trimethylsilyloxy)ethylrhodoximes L—[Rh]—CH 2CH 2OSiMe 3 (L = PPh 3, 4 ; L = py, 5 ). Treatment of complex 1 with acetic anhydride resulted in formation of the 2‐(acet oxy)ethyl complex Ph 3P—[Rh]—CH 2CH 2OAc ( 6 ). All complexes 1 — 6 were isolated in good yields (55—71 %). Their identities were confirmed by NMR spectroscopic investigations ( 1 — 6 : 1H, 13C; 1 , 4 , 6 : 31P) and for [Rh(CH 2CH 2OH)(dmgH) 2(PPh 3)]·CHCl 3·1/2H 2O ( 1 ·CHCl 3·1/2H 2O) and py—[Rh]—CH 2CH 2OSiMe 3 ( 5 ) by X‐ray diffraction analyses, too. In both molecules the rhodium atoms are distorted octahedrally coordinated with triphenylphosphine and the organo ligands (CH 2CH 2OH and CH 2CH 2OSiMe 3, respectively) in mutual trans position. Solutions of 1 in dmf decomposed within several weeks yielding a hydroxyrhodoxime complex “Ph 3P—[Rh]—OH”. X‐ray diffraction analysis exhibited that crystals of this complex have the composition [{Rh(dmg)(dmgH) (H 2O)(PPh 3)} 2]·4dmf ( 7 ) consisting of centrosymmetrical dimers. The rhodium atom is distorted octahedrally coordinated. Axial ligands are PPh 3 and H 2O. One of the two dimethylglyoximato ligands is doubly deprotonated. Thus, only one intramolecular O—H···O hydrogen bridge (O···O 2.447(9)Å) is formed in the equatorial plane. The other two oxygen atoms of dmgH — and dmg 2—, respectively, act as hydrogen acceptors each forming a strong (intermolecular) O···H′—O′ hydrogen bridge to the H′ 2O′ ligand of the other molecule (O···O′ 2.58(2)/2.57(2)Å). 相似文献
4.
The products in inductively coupled plasma excited in organosilicic compounds were studied on chemical structures by spectroscopic methods. Plasma-polymerized tetramethylsilane (PA) contains not only Si? CH 3 groups but also Si? H groups on IR and 29Si-NMR analyses. 13C-NMR spectrum of PA reveals that the crosslinked structure of PA is mainly constructed of Ch 2 and CH groups. Plasma-polymerized octamethyleyclotetrasiloxane (PD 4) is composed of Si? CH 3 and Si? O groups. 13C- and 29Si-NMR spectra of PD 4 point out the highly preservation of the structural units similar to the monomer. These data of PD 4 suggest that PD 4 is formed from the ring-opening polymerization by cleavages of Si? O bonds. 13C-NMR spectrum of poly[methyltrimethoxysilane] (PT) indicates the existence of CH 3? O groups, meanwhile its 29Si-NMR analysis concludes that PT is chiefly composed of the structural units similar to the monomer. The surface analyses by XPS of PA, PD 4 and PT suggest that these organosilicic plasma polymers resemble their starting materials. 相似文献
5.
The Cluster Azides M 2[Nb 6Cl 12(N 3) 6]·(H 2O) 4—x (M = Ca, Sr, Ba) The isotypic cluster compounds M 2[Nb 6Cl 12(N 3) 6] · (H 2O) 4—x (M = Ca (1) , M = Sr (2) and M = Ba (3) ) have been synthesized by the reaction of an aequeous solution of Nb 6Cl 14 with M(N 3) 2. 1 , 2 and 3 crystallize in the space group Fd3¯ (No. 227) with the lattice constants a = 1990.03(23), 2015.60(12) and 2043, 64(11) pm, respectively. All compounds contain isolated 16e — clusters whose terminal positions are all occupied by orientationally disordered azide ligands. 相似文献
6.
Alkali Metal Tetraethinylozincates and ‐cadmates A I2M(C 2H) 4 (A I = Na — Cs, M = Zn, Cd): Synthesis, Crystal Structures, and Spectroscopic Properties By reaction of A IC 2H (A I = Na — Cs) with divalent zinc and cadmium salts in liquid ammonia the alkali metal tetraethinylozincates and ‐cadmates A I2M(C 2H) 4 (M = Zn, Cd) were accessible as polycrystalline powders. While Na 2M(C 2H) 4 is amorphous to X‐rays and the crystal structure of Cs 2Zn(C 2H) 4 could not be solved up to now, the remaining compounds are isotypic to the already known crystal structures of the potassium compounds, as was deduced from powder diffraction with X‐rays and synchrotron radiation. They crystallise in the tetragonal space group I41a, contain [M(C 2H) 4] 2— tetrahedra and show structural relationships to the scheelit and anatas structure types. Raman spectroscopic investigations confirm the existence of tetrahedral fragments with C‐C triple bonds in the alkali as well as in the amorphous alkaline earth metal compounds A IIM(C 2H) 4 (A II = Mg — Ba, M = Zn, Cd). 相似文献
7.
Reactions of π-cyclopentadienylbis(triphenylphosphine)rhodium(I) (I) with alkyl halides, olefins, acetylenes, carbon disulfide and elementary sulfur have been investigated. Methyl iodide gives the oxidative-addition product [πC 5H 5 Rh(PPh 3) 2CH 3]I but isopropyl iodide produces the alkyl substituted-cyclopentadienyl complex (π-i-C 3H 7C 5H 4)Rh(PPh 3)I 2. Under a nitrogen atmosphere, olefins and acetylenes give compounds of the composition π-C 5H 5 Rh(PPh 3)(L) (L = CH 2—CHCN, CH 2—CHCO 2CH 3, CH 3O 2—CCOO 2CH 3).In the presence of air, however, complexes of the composition π-C 5H 5Rh(L) 2 (L = CH 2—CHCN, CH 2—CHCO 2CH 3, CH 2—C(CH 3)CN) and π-C 5H 5Rh(L) 3 (L = CH 3O 2 CC—CCO 2 CH 3, PhC—CCO 2 CH 3) are formed. The reaction of carbon disulfide or sulfur with (I) also gives the compounds π-C 5H 5Rh(PPh 3)(L) (L = CS 2, CS 3, S 5). 相似文献
8.
High-boiling hydrocarbons often yield abundant [M — 2H] +. ions under the conditions of field desorption mass spectrometry (FDMS). This work evaluated [M — 2H] +. formation from various saturated and aromatic compounds. The most intense [M — 2H] +. signals observed resulted from the analysis of saturated compounds containing long and branched chains. The presence of an aromatic ring in a molecule, however, strongly diminished [M — 2H] +. formation during FDMS. Experiments involving manipulation of the applied potential between the FD anode and cathode reveal the strong field dependence of this phenomenon. At a potential difference of 10 kV, strong [M — 2H] +. formation occurred for samples including squalane, hexatriacontane ( C36 n-alkane) and a Polywax 655 mixture. Analyses of the same samples conducted at a potential difference of 4 kV produced only weak (if measurable) [M — 2H +.] signals. The magnitude of [M — 2H] +. formation also decreased as the sample quantity decreased. 相似文献
9.
The polyfluorinated title compounds, [ M Cl 2(C 16H 16F 4N 2O 2)] or [4,4′‐(HCF 2CH 2OCH 2) 2‐2,2′‐bpy] M Cl 2 [ M = Pd, ( 1 ), and M = Pt, ( 2 )], have –C(H α) 2OC(H β) 2CF 2H side chains with H‐atom donors at the α and β sites. The structures of ( 1 ) and ( 2 ) are isomorphous, with the nearly planar (bpy) M Cl 2 molecules stacked in columns. Within one column, π‐dimer pairs alternate between a π‐dimer pair reinforced with C—H…Cl hydrogen bonds (α,α) and a π‐dimer pair reinforced with C—H β…F(—C) interactions (abbreviated as C—H β…F—C,C—H β…F—C). The compounds [4,4′‐(CF 3CH 2OCH 2) 2‐2,2′‐bpy] M Cl 2 [ M = Pd, ( 3 ), and M = Pt, ( 4 )] have been reported to be isomorphous [Lu et al. (2012). J. Fluorine Chem. 137 , 54–56], yet with disorder in the fluorous regions. The molecules of ( 3 ) [or ( 4 )] also form similar stacks, but with alternating π‐dimer pairs between the (α,β; α,β) and (β,β) forms. Through (C—)H…Cl hydrogen‐bond interactions, one molecule of ( 1 ) [or ( 2 )] is expanded into an aggregate of two inversion‐related π‐dimer pairs, one pair in the (α,α) form and the other pair in the (C—H β…F—C,C—H β…F—C) form, with the plane normals making an interplanar angle of 58.24 (3)°. Due to the demands of maintaining a high coordination number around the metal‐bound Cl atoms in molecule ( 1 ) [or ( 2 )], the ponytails of molecule ( 1 ) [or ( 2 )] bend outward; in contrast, the ponytails of molecule ( 3 ) [or ( 4 )] bend inward. 相似文献
10.
Polysulfonylamines. CLII. Crystal Structures of Metal Di(methanesulfonyl) amides. 6. Three Layer Structures: The Isotypic Binary Compounds M[(MeSO 2) 2N] 2 (M = Sr, Pb) and the Ethanol Solvate Pb[(MeSO 2) 2N] 2 · EtOH Low‐temperature X‐ray crystal structures are reported for the layer compounds SrA 2 (monoclinic, space group P2 1/ n, Z′ = 1), PbA 2 (isotypic and isostructural with SrA 2), and PbA 2·EtOH (triclinic, P1¯, Z′ = 1), where A — denotes the anion obtained by deprotonation of the strong NH acid (MeSO 2) 2NH. The ternary compound appears to be the first crystallographically established ethanol solvate of a lead(II) complex. In the two‐dimensional coordination networks, the cations adopt either a distorted cubic or, in the solvate, an irregular (O 6N 2)‐octacoordination, the metal centres of the isotypic structures forming close contacts to two (O, N)‐chelating and four κ 1O‐bonding anions, whereas in the solvate one of the latter ligands is displaced by an EtOH molecule. In the isotypic structures, the Pb—O distances are systematically longer than the Sr—O distances and the Pb—N bonds shorter than the Sr—N bonds, which correlates with the softer character of Pb 2+ as compared to Sr 2+. The 6s lone pair on Pb 2+ is stereochemically inactive in both lead compounds. Analogies and discrepancies between the layer architectures are discussed in detail, including an evaluation of short C—H···O contacts in terms of weak hydrogen bonding. Two complexes of composition PbA 2·2 L, where L is pyridine or 1, 10‐phenanthroline, have been synthesized and characterized by analytical methods. 相似文献
11.
A procedure was developed for the synthesis of mononuclear first row transition metal coordination compounds with adamantane-1-carboxylate (AdCO2), which allowed the synthesis of complexes NBu4[M(AdCO2)3], where MII = Mn, Ni, Co, Zn. The X-ray diffraction study showed that all AdCO2 act as chelating ligands, which is the main distinguishing structural feature of the synthesized compounds. The formation of four-membered metallocycles leads to a small O—M—O angle (58.4–63.0°), resulting in the distorted trigonal-prismatic environment of the central atom in the coordination anions [M(AdCO2)3]?. Under similar conditions of the synthesis, CuII forms the complex (NBu4)2[Cu(AdCO2)2(SO4)] existing in two differently colored modifications (green and light blue), which is due to a small difference in the environment of CuII in the solid state. Upon heating above 150°C, the light blue modification is transformed into the green modification. Using 1,3-diphenyltriazene (HL), it was demonstrated that the developed synthetic approach is applicable to the preparation of compounds, in which the coordination anions [ML3]? also contain only four-membered chelate metallocycles with the N—M—N angle tightened at the metal atom. The compounds NBu4[ML3], where MII = Co and Ni, were isolated in individual state and were structurally characterized. 相似文献
12.
Syntheses and Characterizations of the First Tris and Tetrakis(trifluoromethyl) Palladates(II) and Platinates(II), [M(CF 3) 3(PPh 3)] — and [M(CF 3) 4] 2— (M = Pd, Pt) Tris(trifluoromethyl)(triphenylphosphino)palladate(II) and platinate(II), [M(CF 3) 3PPh 3] —, and the tetrakis(trifluoromethyl)metallates, [M(CF 3) 4] 2— (M = Pd, Pt), are prepared from the reactions of [MCl 2(PPh 3) 2] and Me 3SiCF 3 / [Me 4N]F or [I(CF 3) 2] — salts in good yields. [Me 4N][M(CF 3) 3(PPh 3)] crystallize isotypically in the orthorhombic space group Pnma (no. 62) with Z = 4. The NMR spectra of the new compounds are described. 相似文献
13.
The infrared spectra (700-200 cm ?1) of 52 complexes of general formula Na[ML 3] or [ML 2B] (where M = a divalent metal ion of the first transition series; L = α-thenoyltrifluoroacetonate or benzoyltrifluoroacetonate anion; B = 2H 2O, 2NH 3, 2pyridine, 2,2'-bipyridine or 1,10-phenanthroline) are discussed. Within each series of complexes with common L and B, the IR band near 400 cm ?1 which exhibits maximum sensitivity to the coordinated metal ion (the sensitivity being in the sequence of crystal field stabilization energies) and which generally occurs in a region free from ligand absorption, is assigned to the metal—oxygen stretching frequency ( v(M—O)). For each series of complexes with common M and L, the magnitude of v(M—O) decreases progressively with increasing ligand field strength of B. This relationship enables the coordinated bases, B, to be arranged in a spectrochemical series which is practically identical with that obtained from electronic spectra. 相似文献
14.
Enthalpies of the overall decomposition reactions MX 2L 2(c) → MX 2(c) + 2L(g) and of the intermediate stepwise loss of ligand, L, where X is Cl or Br; L is 3-chloropyridine, 3-bromopyridine, 2-chloropyridine, 2-bromopyridine, or 2-methoxypyridine; and M is Mn, Ni, Cu, or Cd have been measured by use of a differential scanning calorimeter. Enthalpies of sublimation of NiCl 2(3-chloropyridine) 2, NiCl 2(3-bromopyridine) 2 and CuCl 2(3-bromopyridine) 2 have been determined. Values of the metal—nitrogen bond dissociation energies in these compounds have been calculated. A value for the specific heat of CuCl 2(2-chloropyridine) 2 is reported. 相似文献
15.
Compounds of formula [M(NO)(PPh 3)(N 4R 2)] (I) (M Rh, Ir; R SO 2? C 6H 4CH 3) have been obtained by the interaction of M(NO)(PPh 3) 3 with p-toluene-sulphonyl azide in benzene. These new compounds are formulated as tetrazene derivatives on the basis of chemical and spectroscopic data. They react with ligands, L, ( e.g. CO, PPh 3 to give pentacoordinated species of formula [M(NO)(PPh 3(L)(N 4R 2)].The tetrazene derivatives yield the new nitrosyl compounds, M(NO)(PPh 3)Cl 2 (II) on treatment with HCl, the nitrogen-containing residue being converted into RN 3 and RNH 2 species. The compounds (II) are coordinatively unsaturated, and react with ligands L in the same manner as compounds (I), giving new derivatives of formula M(NO)(PPh 3)(L)Cl 2.IR and NMR spectra of the new compounds are reported and discussed. The presence in solution of a structure in which the chelate tetrazene ring has opened { e.g. [M(NO)(PPh 3)(NR)(N 3R)]} is suggested by NMR studies. 相似文献
16.
Five coordination compounds of bismuth, lanthanum and praseodymium nitrate with the oxygen‐coordinating chelate ligand ( iPrO) 2(O)PCH 2P(O)(O iPr) 2 (L) are reported: [Bi(NO 3) 3(L) 2] ( 1 ), [La(NO 3) 3(L) 2] ( 2 ), [Pr(NO 3) 3(L) 2] ( 3 ), [La(NO 3) 3(L)(H 2O)] ( 4 ) and [Pr(NO 3) 3(L)(H 2O)] ( 5 ). The compounds were characterized by means of single crystal X‐ray crystallography, 1H and 31P NMR spectroscopy in solution, solid‐state 31P NMR spectroscopy, IR spectroscopy, DTA‐TG measurements ( 1 , 2 and 4 ), conductometry and electrospray ionization mass spectrometry (ESI‐MS). In addition, DFT calculations for model compounds of 1 and 2 support our experimental work. In the solid state mononuclear coordination compounds were observed for 1 — 3 , whereas compounds 4 and 5 gave one‐dimensional hydrogen‐bonded polymers via water‐nitrate coordination. Despite of the similar ionic radii of bismuth(III), lanthanum(III) and praseodymium(III) for a given coordination number the bismuth and lanthanide compounds 1 — 3 are not isostructural. The bismuth compound 1 shows a 9‐coordinate bismuth atom whereas lanthanum(III) and praseodymium(III) atoms are 10‐coordinate in the lanthanide complexes 2 — 5 . The general LnO 10 coordination motif in compounds 2 — 5 is best described as a distorted bi‐capped square antiprism. The BiO 9 polyhedron might be deduced from the LnO 10 polyhedron by replacing one oxygen ligand with a stereochemically active lone pair. The one‐to‐one complexes 4 and 5 dissociate in solution to give the corresponding one‐to‐two complexes 2 and 3 , respectively, and solvated Ln(NO 3) 3. In contrast to the lanthanides, the one‐to‐two bismuth complex 1 is less stable in CH 3CN solution and partially dissociates to give solvated Bi(NO 3) 3 and ( iPrO) 2(O)PCH 2P(O)(O iPr) 2. 相似文献
17.
The effects of the complexes of the type M(L) 2(nia) 2 (M = Cd or Zn; L = acetate (ac) or NCS −; nia = nicotinamida) on reduction of chlorophyll content in suspensions of Chlorella vulgaris and inhibition of photosynthetic electron transport in spinach chloroplasts were investigated. The inhibitory effects of
the studied compounds depended on the central metal atom as well as on the structure of L ligands. In general, the toxicity
of M(NCS) 2(nia) 2 was higher than that of M(ac) 2(nia) 2 and the compounds containing cadmium were more toxic than those with Zn.
Dry mass of plants cultivated in the presence of the studied complexes ( c = 100 μmol dm −3) showed a decrease related to control plants. The uptaken metal (Cd or Zn) was accumulated mainly in the roots. In general,
application of M(ac) 2(nia) 2 compounds led to higher accumulated metal content in dry mass of plant organs (in mg g −1) related to M(NCS) 2(nia) 2 administration. In plants treated with Zn(NCS) 2(nia) 2 lower content of essential metals Mn and Cu was found than in those treated with Zn(ac) 2(nia) 2.
Toxic effects of the studied M(L) 2(nia) 2 compounds could be caused by exchange of their ligands with potential “biotic S-, O-, and N-donor ligands” occurring in the
plant cells. 相似文献
18.
Perfluoromethyl Element Ligands. XXIX. Preparation and Spectroscopic Investigation of M(CO) 4L 2 Complexes (M ? Cr, Mo, W; L ? Me 2PSMe, Me 2PSeMe, (CF 3) 2PSMe, (CF 3) 2PSMe) The complexes M(CO) 4L 2 (see Inhaltsübersicht) have been prepared by the reaction of tetracarbonyl norbornadiene metal compounds M(CO) 4NBD with L at room temperature or 35°C, respectively. The cis-complexes formed in the first step undergo rearrangement to trans-isomers at higher temperatures. New compounds have been characterized by analytical and spectroscopic (IR, NMR, MS) methods. 相似文献
19.
The article reviews results of research that was initially aiming at complexes containing new and unusual [M—N—E] element combinations (M = transition metal, E = main group element), but soon turned into studies on model complexes for metal enzymes such as nitrogenases, hydrogenases or CO dehydrogenases, because several of the resulting [M—N—E] complexes exhibited reactions relevant to these enzymes. It could be shown that alkylation of transition metal thiolate nitride complexes gives alkylimido complexes when bulky and mild alkylation reagents, e.g. Ph 3C +, are used. Hydride addition to [Ru(NO)(py buS 4)] + yielded [Ru(HNO)(py buS 4)], which contains a bifurcated [M—N(X, Y)] bridge. The diazene complex [μ‐N 2H 2{Ru(PCy 3)(S 4)} 2] undergoes H +/D + and H +/D 2 exchange reactions that enabled to rationalize the until then inexplicable ‘N 2 dependent HD formation’ catalyzed by nitrogenases. Out of a larger number of [Ni(NE)(S 3)] complexes, the compound [Ni(NHPPr 3)(S 3)] proved capable to model structure and reactivity features of [NiFe] hydrogenases. The [Ni(L)(S 3)] complexes with L = N 3— and N(SiMe 3) 2— exhibit extremely high reactivity towards CO, CO 2 and SO 2. The reactions lead to NCO —, CN — and NSO — complexes and bear potential relevance for carbon monoxide dehydrogenase reactions. 相似文献
20.
Preparation, Characterization and Reaction Behaviour of Sodium and Potassium Hydridosilylamides R 2(H)Si—N(M)R′ (M = Na, K) — Crystal Structure of [(Me 3C) 2(H)Si—N(K)SiMe 3] 2 · THF The alkali metal hydridosilylamides R 2(H)Si—N(M)R′ 1a‐Na — 1d—Na and 1a‐K — 1d‐K ( a : R = Me, R′ = CMe 3; b : R = Me, R′ = SiMe 3; c : R = Me, R′ = Si(H)Me 2; d : R = CMe 3, R′= SiMe 3) have been prepared by reaction of the corresponding hydridosilylamines 1a — 1d with alkali metal M (M = Na, K) in presence of styrene or with alkali metal hydrides MH (M = Na, K). With NaNH 2 in toluene Me 2(H)Si—NHCMe 3 ( 1a ) reacted not under metalation but under nucleophilic substitution of the H(Si) atom to give Me 2(NaNH)Si—NHCMe 3 ( 5 ). In the reaction of Me 2(H)Si—NHSiMe 3 ( 1b ) with NaNH 2 intoluene a mixture of Me 2(NaNH)Si—NHSiMe 3 and Me 2(H)Si—N(Na)SiMe 3 ( 1b‐Na ) was obtained. The hydridosilylamides have been characterized spectroscopically. The spectroscopic data of these amides and of the corresponding lithium derivatives are discussed. The 29Si‐NMR‐chemical shifts and the 29Si— 1H coupling constants of homologous alkali metal hydridosilylamides R 2(H)Si—N(M)R′ (M = Li, Na, K) are depending on the alkali metal. With increasing of the ionic character of the M—N bond M = K > Na > Li the 29Si‐NMR‐signals are shifted upfield and the 29Si— 1H coupling constants except for compounds (Me 3C)(H)Si—N(M)SiMe 3 are decreased. The reaction behaviour of the amides 1a‐Na — 1c‐Na and 1a‐K — 1c‐K was investigated toward chlorotrimethylsilane in tetrahydrofuran (THF) and in n‐pentane. In THF the amides produced just like the analogous lithium amides the corresponding N‐silylation products Me 2(H)Si—N(SiMe 3)R′ ( 2a — 2c ) in high yields. The reaction of the sodium amides with chlorotrimethylsilane in nonpolar solvent n‐pentane produced from 1a‐Na the cyclodisilazane [Me 2Si—NCMe 3] 2 ( 8a ), from 1b‐Na and 1‐Na mixtures of cyclodisilazane [Me 2Si—NR′] 2 ( 8b , 8c ) and N‐silylation product 2b , 2c . In contrast to 1b‐Na and 1c‐Na and to the analogous lithium amides the reaction of 1b‐K and 1c‐K with chlorotrimethylsilane afforded the N‐silylation products Me 2(H)Si—N(SiMe 3)R′ ( 2b , 2c ) in high yields. The amide [(Me 3C) 2(H)Si—N(K)SiMe 3] 2·THF ( 9 ) crystallizes in the space group C2/c with Z = 4. The central part of the molecule is a planar four‐membered K 2N 2 ring. One potassium atom is coordinated by two nitrogen atoms and the other one by two nitrogen atoms and one oxygen atom. Furthermore K···H(Si) and K···CH 3 contacts exist in 9 . The K—N distances in the K 2N 2 ring differ marginally. 相似文献
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