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1.
>From Small Fragments to New Poly‐alkoxo‐oxo‐metalate Derivatives: Syntheses and Crystal Structures of K4[VIV12O12(OCH3)16(C4O4)6], Cs10[VIV24O24(OCH3)32(C4O4)12][VIV8O8(OCH3)16(C2O4)], and M2[VIV8O8(OCH3)16(VIVOF4)] (M = [N(nBu)4] or [NEt4]) By solvothermal reaction of ortho‐vanadicacid ester [VO(OMe)3] with squaric acid and potassium or caesium hydroxide the compounds K4[VIV12O12(OCH3)16(C4O4)6] ( 2 ) and Cs10[VIV24O24(OCH3)32(C4O4)12][VIV8O8(OCH3)16(C2O4)] ( 3 ) could be syntesized. With tetra‐n‐butyl‐ or tetra‐n‐ethylammonium fluoride [N(nBu)4]2[VIV8O8(OCH3)16(VIVOF4)] ( 4 ) and [N(Et)4]2[VIV8O8(OCH3)16(VIVOF4)] ( 5 ) could be isolated. In 2 and 3 the corners of a tetrahedron or cube resp. are occupied by {(VO)3(OMe)4} groups and connected along the edges of the tetrahedron resp. cube by six or twelve resp. squarato‐groups. The octanuclear anions in the compounds 3 , 4 , and 5 are assumedly built up by fragments of the ortho‐vanadicacid ester [VO(OMe)3]. Around the anions C2O42— or VOF4 these oligormeric chains are closed to a ring . Crystal data: 2 , tetragonal, P43, a = 18.166(3)Å, c = 29.165(7)Å, V = 9625(3)Å3, Z = 4, dc = 1.469 gcm—3; 3 , orthorhombic, Pbca, a = 29.493(5)Å, b = 25.564(4)Å, c = 31.076Å, V = 23430(6)Å3, Z = 4, dc = 1.892 gcm—3; 4 , monoclinic, P21/n, a = 9.528(1)Å, b = 23.021(2)Å, c = 19.303(2)Å, β = 92.570(2)°, V = 4229.8(5)Å3, Z = 2, dc = 1.391 gcm—3; 5 , monoclinic, P21/n, a = 16.451(2)Å, b = 8.806(1)Å, c = 23.812(1)Å, β = 102.423(2)°, V = 3368.7(6)Å3, Z = 2, dc = 1.534 gcm—3.  相似文献   

2.
The reaction of CdCl2 or CdBr2with LiBH4, in ether yields no pure Cd(BH4)2, but Li2Cd(BH4)4 was isolated as an oily etherate. Similarly, NaCd(BH4)3 was obtained from CdCl2 and NaBH4 in ether and tetrahydrofurane as solvents. LiCd(BH4)3 and NaCd(BH4)3 were also formed from the components in ether solution. In these solutions Cd migrates to the anode confirming their formulation as tetrahydroborato-cadmates. Cadmiumtetrahydroborate was formed in the reaction of cadmium methoxide with diborane in tetrahydrofurane (THF) and isolated as crystalline solvates. It reacts with pyridine to give Cd(BH4)2 · 3 NC5H5 and with NH3 to yield Cd(NH3)6(BH4)2.  相似文献   

3.
We report the synthesis and the characterization (elemental analysis, FT-IR spectroscopy, thermal methods and molar conductivity measurements) of the mixed complexes of zinc with acetate and 3-amino-5-methylpyrazole, HL 1, [Zn(OAc)2(HL1)2], or 3-amino-5-phenylpyrazole, HL 2 [Zn(OAc)2(HL2)2], or 4-acetyl-3-amino-5-methylpyrazole, HL 3, [Zn(OAc)(L3)(HL3)]2, with isothiocyanate and HL 2 [Zn(SCN)2(HL2)2], or HL 3 [Zn(SCN)2(HL3)2], and with nitrate, isothiocyanate and 3,5-dimethyl-1-carboxamidinepyrazole, HL 4 [Zn(NO3)(NCS)(HL4)2]. The thermal decomposition of the complexes is generally continuous resulting zinc oxide as end product,except [Zn(OAc)(L3)(HL3)]2 in which case a well-defined intermediate was observed between 570–620 K. On the basis of the IR spectra and elemental analysis data of the intermediate a decomposition scheme is proposed. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

4.
Metal Tetrahydridoborates and Tetrahydridoborato Metalates. 14. Chloro Tetrahydridoborates of calcium and Strontium The action of hydrogen chloride on E(BH4)2 (E ? Ca, Se) in a 1:1 mole ratio in tetrahydrofuran yields the title compounds isolated as their tetrahydrofuran adducts. No intermediates were detected by 11B n.m.r. spectroscopy in the reaction of methanol with Ca(BH4)2. The final product is Ca[B(OCH3)4]2 · THF.  相似文献   

5.
The standard enthalpies of reaction of four zinc hydroxide nitrates Zn(OH)(NO3)-H2O, Zn3(OH)4(NO3)2, Zn5(OH)8(NO3)2·2H2O et Zn5(OH)8(NO3)2 and zinc oxide with a solution of nitric acid (2N) were measured in a solution calorimeter. These results, combined with auxiliary thermochemical values from the literature, yielded values of ?429.34, ?442.41, ?897.41 and ?750.70 kcal mol?1 respectively, for the molar enthalpies of formation of these zinc hydroxide nitrates.  相似文献   

6.
Reactions of [Pt2(μ-S)2(PPh3)4] with zinc acetate and an ancillary chelating ligand L (HL = 8-hydroxyquinoline, 8-tosylaminoquinoline or maltol) with added trimethylamine in methanol give new cationic platinum–zinc sulfide aggregates [Pt2(μ-S)2(PPh3)4ZnL]+, isolated as their BF4? salts. The complexes were characterized by NMR spectroscopy, ESI mass spectrometry, microelemental analysis, and an X-ray structure determination of the tosylamidoquinoline derivative [Pt2(μ-S)2(PPh3)4Zn(TAQ)]BF4, which showed a distorted tetrahedral coordination geometry at zinc. Additional examples, containing picolinate, dithiocarbamate, or dithiophosphinate ligands were also synthesized and partly characterized in order to demonstrate a wider range of available derivatives.  相似文献   

7.
The reaction scheme of thermal decomposition for four zinc hydroxynitrates was investigated by means of differential scanning calorimetry, thermogravimetry, mass spectrometry, and radiocrystallography. The thermal transformation of Zn(OH)(NO3) · H2O and of Zn3(OH)4(NO3)2 involves the formation of gaseous water and nitric acid from an actual chemical reaction. This reaction is not observed for Zn5(OH)8(NO3)2 · 2H2O and Zn5(OH)8(NO3)2. These results show that the formation of gaseous nitric acid molecules inside the solids is specific to hydroxynitrates of divalent metals M, whose lamellar crystalline structure is characterized by a stacking of hexagonal close-packed layers of formula MX2+m, where m = 0 or 1 and X = OH?, H2O, or NO?3.  相似文献   

8.
The reaction of potassium 2,5‐bis[N‐(2,6‐diisopropylphenyl)iminomethyl]pyrrolyl [(dip2‐pyr)K] with the borohydrides of the larger rare‐earth metals, [Ln(BH4)3(thf)3] (Ln=La, Nd), afforded the expected products [Ln(BH4)2(dip2‐pyr)(thf)2]. As usual, the trisborohydrides reacted like pseudohalide compounds forming KBH4 as a by‐product. To compare the reactivity with the analogous halides, the dimeric neodymium complex [NdCl2(dip2‐pyr)(thf)]2 was prepared by reaction of [(dip2‐pyr)K] with anhydrous NdCl3. Reaction of [(dip2‐pyr)K] with the borohydrides of the smaller rare‐earth metals, [Sc(BH4)3(thf)2] and [Lu(BH4)3(thf)3], resulted in a redox reaction of the BH4? group with one of the Schiff base functions of the ligand. In the resulting products, [Ln(BH4){(dip)(dip‐BH3)‐pyr}(thf)2] (Ln=Sc, Lu), a dinegatively charged ligand with a new amido function, a Schiff base, and the pyrrolyl function is bound to the metal atom. The by‐product of the reaction of the BH4? anion with the Schiff base function (a BH3 molecule) is trapped in a unique reaction mode in the coordination sphere of the metal complex. The BH3 molecule coordinates in an η2 fashion to the metal atom. The rare‐earth‐metal atoms are surrounded by the η2‐coordinated BH3 molecule, the η3‐coordinated BH4? anion, two THF molecules, and the nitrogen atoms from the Schiff base and the pyrrolyl function. All new compounds were characterized by single‐crystal X‐ray diffraction. Low‐temperature X‐ray diffraction data at 6 K were collected to locate the hydrogen atoms of [Lu(BH4){(dip)(dip‐BH3)‐pyr}(thf)2]. The (DIP2‐pyr)? borohydride and chloride complexes of neodymium, [Nd(BH4)2(dip2‐pyr)(thf)2] and [NdCl2(dip2‐pyr)(thf)]2, were also used as Ziegler–Natta catalysts for the polymerization of 1,3‐butadiene to yield poly(cis‐1,4‐butadiene). Very high activities and good cis selectivities were observed by using each of these complexes as a catalyst in the presence of various cocatalyst mixtures.  相似文献   

9.
Zusammenfassung Beim Umsatz von Chlorid-di-borhydriden der Seltenerdelemente mit Natriummethoxid in Tetrahydrofuran erfolgt Reaktion nach der Gleichung LnCl(BH4)2+2 NaOCH3=Ln(OCH3)2(BH4)+NaCl+NaBH4; gleichzeitig tritt teilweise Substitution des Hydridwasserstoffs durch OCH3 ein. Das Primärprodukt geht über isolierbare Zwischenstufen in ein Endprodukt von der Summenformel LnB (H, OCH3)3 über, dessen wahrscheinlichste analytische Zusammensetzung LnBH2OCH3 ist. Der Verlauf der Primärreaktion wurde durch Ausführung verschiedener Reaktionswege gesichert; insgesamt ergaben sich 9 neue Verbindungen.  相似文献   

10.
Metal Tetrahydroborates and Tetrahydroboratometallates. VIII. Preparation and Properties of Dimeric Halogenotitanium(III) Bis(tetrahydroborates) [XTi(BH4)2]2 Chlorotitanium(III)bis(tetrahydroborate) is produced besides Ti(BH4)3 in the reaction of TiCl4 vapour with solid LiBH4. It forms in 72% yield by using n-pentane as reaction medium. BrTi(BH4)2 and ITi(BH4)2 were prepared similarly. All these compounds are dimerized via halogen bridges. The bridge opens by addition of tetrahydrofurane to ClTi(BH4)2 with disproportionation to yield Ti(BH4)3 · nOC4H8 and TiCl3 · mOC4H8 contrary to diethylether. The ir, 11B-nmr and electronic spectra of the halogenotitanium(III) bis(tetrahydroborates) are discussed.  相似文献   

11.
Photoreaction of diaminosubstituted-phosphiteborane, BH3P(NMeCH2)2(OMe) with a methyl molybdenum complex, (η5-C5R5)Mo(CO)3Me (R5 = Me5, Me4H, H5) yielded a phosphiteboryl molybdenum complex, (η5-C5R5)Mo(CO)3BH2{P(NMeCH2)2(OMe)} (R5 = Me5: 2, Me4H: 3, H5: 4). In the reaction of 2 with MeI, the Mo–B bond was activated to give (η5-C5Me5)Mo(CO)3Me, in the reaction with PMe3, the B–P bond was activated to give (η5-C5Me5)Mo(CO)3(BH2PMe3). Complex 2 in solution was gradually converted into (η5-C5Me5)MoH(CO)2{P(NMeCH2)2(OMe)} (8) via the B–H bond activation of 2. Structures of 2, 3, and 8 were determined by single crystal X-ray diffraction studies.  相似文献   

12.
Reactions of Alcohols and Mercaptans with Tetraphosphorus Trichalcogenide Diiodides α-P4E3(I)R and α-P4E3R2 (R = -OCH3, -OC2H5, -OCH(CH3)2, -OC(CH3)3 and -OC6H5) have been detected in the reaction solutions of α-P4E3I2 (E = S, Se) with alcohols in the presence of triethylamine, or with trimethyltin alkoxides in CS2. β-P4S3I2 reacted with methanol at 243 K in CS2 to yield β-P4S3(I)OCH3, β-P4S3(OCH3)exo(OCH3)endo, and β-P4S3[(OCH3)exo]2. The thiolates α-P4Se3R2′ (R′ = -SC2H5, -n-SC5H11, -n-SC7H15, -SC(CH3)3 and -SC6H5) were found in reaction solutions of α-P4Se3I2 with thiols HR′. The 31P NMR data of these compounds are given.  相似文献   

13.
The hydrolysis of hydro(pyrrolyl-l)borates ([BHn(NC4H4)4-n], n = 1,2,3) can be treated as a kinetically one-step reaction outside of the mildly acidic region. In strongly acidic medium the hydrolysis takes place in a stepwise manner; the intermediates (boranes and the cationic boron compounds) being hydrolyzed more slowly than the borate anion. In the first step of the hydrolysis of [BH3(NC4H4)] the B---H bond, while in case of [BH2(NC4H4)2] and [BH(NC4H4)3] the B---N bond is breaking.In neutral and mildly alkaline medium, the hydrolysis is a general acid catalyzed reaction (A---SE2 mechanism). It becomes to a special H+-ion catalyzed reaction (A-1 mechanism) in strongly alkaline region since the protonated intermediate can be reversed to the original borate upon reaction with the OH ion. The hydrolysis presumably takes place through an intermediate which is protonated on the pyrrolyl nitrogen. Concomitant to the hydrolysis an isotopic exchange reaction was observed on the Cα and Cβ atoms of the pyrrolyl group in heavy water. In the hydrolysis of the [BH3(NC4H4)]-anion the N-protonated intermediate is assumed to be able to reverse to the original borate even in acidic or neutral region, at least in part.  相似文献   

14.

A novel ferrocenyl dimer [Zn2(μ-OOCFc)4(3-PyCOOCH3)2] (Fc=(η5-C5H5)Fe(η5-C5H4)), 1, was obtained by the reaction of Zn(OAc)2·2H2O with sodium ferrocenecarboxylate and 1,4-butanediol dinicotinate in methanol solution. X-ray structural analysis reveals that the compound contains two zinc(II) centers symmetrically bridged by four ferrocenecarboxylate anions as O,O′-bridging ligands, leading to a dimeric tetrabridged [Zn2(μ-OOCFc)4] core. The zinc(II) ion is in a distorted octahedral environment with four oxygen atoms from four distinct ferrocenecarboxylates, a nitrogen atom from the ligand NC5H4CO2CH3, and another zinc atom. The symmetry of the complex in the paddle-wheel structure brings the metal centers close, the Zn … Zn intradimer distance being 2.934(11) Å. It is the first example of a zinc(II) dimer with ferrocenecarboxylate anion ligands. Its thermal properties were measured in air.  相似文献   

15.
We studied the conditions for the photochemical formation of the NaZn excimer in the excited 22Π state using Na2(21Π u )+Zn→NaZn(22Π)+Na reaction. The Na-Zn vapor mixture was prepared in the heat-pipe oven with the well defined column density and temperature. The Na and Zn atom densities in the vapor mixture were controlled by the preparation of the alloy with different mole fraction ratios of the relevant components in the solid phase. The Na densities were determined from the total absorption coefficient at Na2 X-B and X-A bands. The cross section for photochemical formation of the NaZn in the 22Π state is estimated to be 17·10?16 cm2 for the laser excitation at 308 nm, measured relative to the cross section of 470·10?16 cm2 for collisional energy transfer Na2(21Π u )+Na→Na2(23Π g )+Na published by Mehdizadeh et al. [2].  相似文献   

16.
A new ammine dual‐cation borohydride, LiMg(BH4)3(NH3)2, has been successfully synthesized simply by ball‐milling of Mg(BH4)2 and LiBH4 ? NH3. Structure analysis of the synthesized LiMg(BH4)3(NH3)2 revealed that it crystallized in the space group P63 (no. 173) with lattice parameters of a=b=8.0002(1) Å, c=8.4276(1) Å, α=β=90°, and γ=120° at 50 °C. A three‐dimensional architecture is built up through corner‐connecting BH4 units. Strong N? H???H? B dihydrogen bonds exist between the NH3 and BH4 units, enabling LiMg(BH4)3(NH3)2 to undergo dehydrogenation at a much lower temperature. Dehydrogenation studies have revealed that the LiMg(BH4)3(NH3)2/LiBH4 composite is able to release over 8 wt % hydrogen below 200 °C, which is comparable to that released by Mg(BH4)3(NH3)2. More importantly, it was found that release of the byproduct NH3 in this system can be completely suppressed by adjusting the ratio of Mg(BH4)2 and LiBH4 ? NH3. This chemical control route highlights a potential method for modifying the dehydrogenation properties of other ammine borohydride systems.  相似文献   

17.
The tetrameric Cu(β-diketonate) alkoxide complex [Cu(thd)(OCH2CH2OCH3)]4 (thd = 2,2,6,6-tetramethyl-3,5-heptanedionate; 1a ) reacts with the alkaline earth metal alkoxides [M(OCH2CH2OCH3)2] (M = Ca, 2a ; M = Sr, 2b ; M = Ba, 2c ) to yield the heteronuclear compounds [Cu2M(thd)3(OCH2CH2OCH3)3] (M = Ca, 6a ; M = Sr, 6b ). These heterometallic complexes were also obtained in the reaction of 1a and the mixed Ca and Sr complexes of β-diketonate-alkoxide [Mx(thd)y(OCH2CH2OCH3)2x?y] (M = Ca, x = 7, y = 6, 3 ; M = Sr, x = 5, y = 3, 4 ), respectively. In comparison, 1a reacts with the analogous [Ba(thd)(OCH2CH2OCH3)] ( 5a ) to yield a[Ba2Cu2(thd)4(OCH3)4(HOCH2CH2OCH3)2] species ( 8a .) The in situ prepared mixed-ligand Ba Compounds [Ba(thd)OR)] (R = CH2CH2OCH2CH2OCH3, ( 5b ); R = CH2CH2CH2OCH3 ( 5c ) react with the corresponding Cu complexes [Cu(thd)(OR)]n (R = CH2CH2OCH2CH2OCH3), n = 4 ( 1b ); R = CH2CH2OCH2CH2OCH3 ( 8b ); R = CH2CH2CH2OCH3 ( 8c ). However, [Cu(hfd)(OCH2CH2OCH3)]4 (hfd = 1,1,1,5,5,5,-hexafluoroacetylacetonate; 1e ) is converted in the presence of 2a–c to the simple metathesis products [M(hfd)2] (M = Ca, Sr, Ba) and [Cu(OCH2CH2OCH3)2]. Crystalline [Ba2Cu2(hfd)2(thd)2(OCH2CH2CH2OCH3)4(HOCH2CH2CH2OCH3)2] ( 9 ) was isolated from the reaction of 1a with in situ prepared [Ba((hfd)OCH2CH2CH2OCH3)] ( 5d ) in 2-, methoxyethanol. X-Ray crystallographic structure determinations are reported for 6a , 6b , 8b , and 8c .  相似文献   

18.
《Polyhedron》1999,18(8-9):1201-1206
Added free ligand, i.e. phenanthroline for (phen)CuBH4 and either phenanthroline or triphenylphosphine for (phen)PPh3CuBH4, causes a progressive change in the mode of attachment of the η2–BH4 moiety from that in the initial complexes to the formation in solution of ionic species of the type [(phen)2Cu]+BH4 and [(phen)(PPh3)2Cu]+BH4, respectively. These changes were indicated by: (i) infrared spectroscopy, which showed both a gradual loss of signals attributed to ν(B–Hb) and δ(BH2) and their replacement with spectra typical of ionic BH4 ion; (ii) an increase in the conductance measured that was consistent with a 1:1 electrolyte; (iii) chemical shift changes in the 11B- and 31P-NMR signals associated with the BH4 and PPh3 moieties, respectively and (iv) a relative increase in signal intensities of the ions detected by electrospray mass spectrometry.  相似文献   

19.
The newly discovered crystal structures of CH3(OCH2CH2)OCH3(LiCF3SO3)2, monoglyme:(LiTf)2, and CH3(OCH2CH2)3OCH3(LiCF3SO3)2, triglyme:(LiTf)2, are briefly described. The coordination of lithium cations and the CF3SO3 anions in these structures is compared with the cation and anion coordination in the crystalline phase of high molecular weight P(EO)3LiCF3SO3. Comparison is also made with the previously reported crystalline phase of CH3(OCH2CH2)2OCH3LiCF3SO3, diglyme:LiTf. A tendency to form trans-gauche-trans conformations for the bond order -O-C-C-O- is noted in adjacent ethylene oxide sequences interacting with a five-coordinate lithium ion.  相似文献   

20.
The isotypic compounds tris(1,2‐ethanedi­amine‐N,N′)­zinc(II) triiodide iodide, [Zn(C2H8N2)3](I3)I, and tris(1,2‐ethanedi­amine‐N,N′)­nickel(II) triiodide iodide, [Ni(C2H8N2)3](I3)I, contain the octahedral [M(en)3]2+ cation, with M = Zn and Ni, in both enantiomeric forms, an essentially linear triiodide anion and an iodide anion. The geometries of the complex ions are as expected, e.g.d(Ni—N) = 2.123 (5), 2.127 (6) and 2.134 (5) Å, and d(Zn—N) = 2.176 (4), 2.193 (4) and 2.210 (4) Å. The shortest contact between the triiodide and iodide ions is 3.979 (1) Å for the nickel compound and 4.013 (1) Å for the zinc compound.  相似文献   

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