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1.
For the 53 neutral atoms from He to Xe in their ground states, the average distances < u> n l , n ′ l ′ in position space and < v> n l , n ′ l ′ in momentum space between an electron in a subshell nl and another electron in a subshell n ′ l ′ are studied, where n and l are the principal and azimuthal quantum numbers of an atomic subshell, respectively. Analysis of 1700 subshell pairs shows that the electron-pair distances < u> n l , n ′ l ′ in position space have an empirical but very accurate linear correlation with a one-electron quantity U n l , n ′ l ′≡L r +S r 2/(3L r ), where L r and S r are the larger and smaller of subshell radii < r> n l and < r> n ′ l ′, respectively. The correlation coefficients are never smaller than 0.999 for the 66 different combinations of two subshells appearing in the 53 atoms. The same is also true in momentum space, and the electron-pair momentum distances < > n l , n ′ l ′ have an accurate linear correlation with a one-electron momentum quantity V n l , n ′ l ′≡L p +S p 2/(3L p ), where L p and S p are the larger and smaller of average subshell momenta < p> n l and < p> n ′ l ′, respectively. Trends in the proportionality constants between < u> n l , n ′ l ′ and U n l , n ′ l ′ and between < > n l , n ′ l ′ and V n l , n ′ l ′ are discussed based on a hydrogenic model for the subshell radial functions. Received: 8 April 1998 / Accepted: 6 July 1998 / Published online: 18 September 1998  相似文献   

2.
Summary Reactions oftrans-[M(N2)2(dppe)2] (A;M=Mo, W;dppe=Ph 2PCH2CH2PPh 2) with ethyldiazoacetate, N2CHCOOEt, yield the bisdiazoalkane speciestrans-[M(N2CHCOOEt)2(dppe)2], upon simple replacement of the dinitrogen ligand by ethyldiazoacetate. However, diazomethane, N2CH2, reacts withA with loss of N2 to give products which we tentatively formulate as containing methylene ligands,trans-[M(CH2)2(dppe)2].
Herstellung von Bisdiazoalkan- und ähnlichen Komplexen aus den Reaktionen von Diazoverbindungen mit Distickstoffkomplexen des Typstrans-[M(N2)2(Ph 2PCH2CH2PPh 2)2] mitM=Mo oder W
Zusammenfassung Die Reaktion vontrans-[M(N2)2(dppe)2] (A:dppe=Ph 2PCH2CH2PPh 2 undM=Mo oder W) mit Ethyldiazoacetat, N2CHCOOEt, ergab nach einfachem Austausch des Distickstoffliganden mit Ethyldiazoacetat die Bisdiazoalkanetrans-[M(N2CHCOOEt)2(dppe)2]. Diazomethan (N2CH2) hingegen reagierte mitA unter Verlust von N2 zu Produkten, die tentativ alstrans-[M(CH2)2(dppe)2] mit Methylenliganden formuliert wurden.
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3.
 The optical absorption, photoluminescence, and photoconductivity spectra of some compounds of the formulas [R(CH2) n NH3] x M y X z , [R(CH2) n NH(CH3)2] x M y X z , [R(CH2) n S(CH3)2] x M y X z , [R(CH2) n SC(NH2)2] x M y X z , and [R(CH2) n SeC(NH2)2] x M y X z (R = organic residue; M = Bi(III), Pb(II), Sn(II), Cu(I), Ag(I) etc; X = I, Br, Cl; n, x, y, z = 0, 1, 2, 3, …) are briefly reviewed, and some new results are reported. The position, intensity, and shape of the excitonic bands depend on the dimensionality and size of the inorganic network as well as on the nature of the M, X, R, and onium moieties.  相似文献   

4.
Disproportionation reactions between (CF 3 CH 2 O) 3 GeNHC 6 H 5 ? n F n and TiCl 4 in petroleum ether (40?60°C) at 0° to ?10°C give (CF 3 CH 2 O) 2 Ge(NHC 6 H 5 ? n F n ) 2 .2TiCl 4 and (CF 3 CH 2 O)Ge(NHC 6 H 5 ? n F n ) 3 . 2TiCl 4 adducts. However, complete disproportionation of (CF 3 CH 2 O) 3 Ge(NHC 6 H 5 ? n F n ) (n = 1,2) occurs at ?55 to ?60°C to give Ge(NHC 6 H 5 ? n F n ) 4 .3TiCl 4 . These complexes give double adducts on reactions with CH 3 NO 2 and CH 3 CN. All the products are characterized by elemental analyses and IR, 1 H, and 19 F NMR spectroscopy. A comparative disproportionation of the germanamines and analogous silanamines is discussed.  相似文献   

5.
Unit cell parameters have been calculated from x-ray powder diffraction data of Mo2Br4 Py 4 (A), Mo2I4 Py 4 (B), Mo2I4 Pic 4 (C), Mo2(SCN)4 Py 4 (D) and Mo2(SCN)4 Pic 4 (E), A, B and C crystallize tetragonal. A witha=9,42,c=15,O2 Å; B witha=9,46,c=14,98 Å and C witha=9,66 andc=15,72 Å D and E crystallize orthorhombic. D witha=10,09,b=9,14,c=15,08 Å; E witha=10,22,b=9,41 andc=15,15 Å.Py=pyridine,Pic=4-methylpyridine.
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6.
Reactions of (m- and p-ClC 6 H 4 NH 2 ), (p-BrC 6 H 4 NO 2 ), and (p-ClCOC 6 H 4 NO 2 ) with sodium O,O′-ditolyl/dibenzylphosphorodithionates, (ArO) 2 PS 2 Na, (Ar = o?, m?, and p?CH 3 C 6 H 4 or –C 6 H 5 CH 2 ) in 1:1 molar ratio in refluxing toluene under anhydrous conditions resulted in the formation of the compounds (ArO) 2 PS 2 C 6 H 4 L and (ArO) 2 PS 2 COC 6 H 4 L (L = NH 2 or NO 2 ) in 87–94% yield. These viscous compounds were characterized by elemental analyses, molecular weight determination, and IR and NMR ( 1 H, 13 C, and 31 P) spectroscopic studies, which revealed a monodentate mode of bonding of the dithiophosphate moiety with the carbon of the phenyl ring of the organic moiety leading to a P–S–C linkage.  相似文献   

7.
The reactions of n-butyl stannonic acid with(PhO) 2 P(O)H leads to the formation of a hexameric tin cage [{(n-BuSn) 3 (PhO) 3 O} 2 {HPO 3 } 4 ].This reaction involves an in situ P─O bond cleavage and the generation of a [HPO 3 ] 2? ion. A direct reaction of six equivalents of n-BuSnO(OH) acid with six equivalents of C 6 H 5 OH and four equivalents of H 3 PO 3 also leads to the formation of same cage structure. A tetranuclear organooxotin cage[(PhCH 2 ) 2 Sn 2 O(O 2 P(OH)-t-Bu) 4 ] 2 has been assembled by debenzylation involving the reaction of (PhCH 2 ) 2 SnCl 2 ,(PhCH 2 ) 2 SnO·H 2 O or (PhCH 2 ) 3 SnCl with two equivalents of t-BuP(O)OH 2 . A half-cage intermediate [(PhCH 2 ) 2 Sn 2 O(O 2 P(OH)-t-Bu) 4 ] has been detected. New organotin cations of the type [n-Bu 2 Sn(H 2 O) 4 ] 2+[2,5-Me 2 -C 6 H 3 SO 3 ]? 2 and {[n-Bu 2 Sn(H 2 O) 3 LSn(H 2 O) 3 (n-Bu) 2 ] 2+[1,5-(SO 3 ) 2 -C 10 H 6 ] 2?} have been obtained in the reactions of n-Bu 2 SnO or (n-Bu 3 Sn) 3 O with 2,5-dimethyl sulfonic acid and 1,5-naphthalene disulfonic acid respectively. These organotin cations form interesting supramolecular structures in the solid state as a result of O─H─···O hydrogen bonding.  相似文献   

8.
The reaction of [PtCl2(COD)] (COD=1,5-cyclooctadiene) with diisopropyl-2-(3-methyl)indolylphosphine (iPr2P(C9H8N)) led to the formation of the platinum(ii ) chlorido complexes, cis-[PtCl2{iPr2P(C9H8N)}2] ( 1 ) and trans-[PtCl2{iPr2P(C9H8N)}2] ( 2 ). The cis-complex 1 reacted with NEt3 yielding the complex cis-[PtCl{κ2-(P,N)-iPr2P(C9H7N)}{iPr2P(C9H8N)}] ( 3 ) bearing a cyclometalated κ2-(P,N)-phosphine ligand, while the isomer 2 with a trans-configuration did not show any reactivity towards NEt3. Treatment of 1 or 3 with (CH3)4NF (TMAF) resulted in the formation of the twofold cyclometalated complex cis-[Pt{κ2-(P,N)-iPr2P(C9H7N)}2] ( 4 ). The molecular structures of the complexes 1–4 were determined by single-crystal X-ray diffraction. The fluorido complex cis-[PtF{κ2-(P,N)-iPr2P(C9H7N)}{iPr2P(C9H8N)}] ⋅ (HF)4 ( 5 ⋅ (HF)4) was formed when complex 4 was treated with different hydrogen fluoride sources. The Pt(ii ) fluorido complex 5 ⋅ (HF)4 exhibits intramolecular hydrogen bonding in its outer coordination sphere between the fluorido ligand and the NH group of the 3-methylindolyl moiety. In contrast to its chlorido analogue 3 , complex 5 ⋅ (HF)4 reacted with CO or the ynamide 1-(2-phenylethynyl)-2-pyrrolidinone to yield the complexes trans-[Pt(CO){κ2-(P,C)-iPr2P(C9H7NCO)}{iPr2P(C9H8N)}][F(HF)4] ( 7 ) and a complex, which we suggest to be cis-[Pt{C=C(Ph)OCN(C3H6)}{κ2-(P,N)-iPr2P(C9H7N)}{iPr2P(C9H8N)}][F(HF)4] ( 9 ), respectively. The structure of 9 was assigned on the basis of DFT calculations as well as NMR and IR data. Hydrogen bonding of HF and NH to fluoride was proven to be crucial for the existence of 7 and 9 .  相似文献   

9.
Three alkali metal acetylides, namely KNaC2, KRbC2, and NaRbC2, were synthesized and characterized by means of X‐ray powder diffraction. KNaC2 and KRbC2 crystallize as a variant of the anti‐PbCl2‐type structure (Pnma, Z = 4), whereas NaRbC2 crystallizes as a variant of the anti‐PbFCl‐type structure (Pmmn, Z = 2). Based on a simple systematic approach developed by Sabrowsky et al. for inter‐alkali metal chalcogenides all known inter‐alkali metal acetylides can be classified into two classes: variants of the anti‐PbCl2 type structure and variants of the anti‐PbFCl type structure. Acetylides with Q(ABC2) ≤ 1.45 crystallize in the anti‐PbCl2‐type structure, whereas for Q(ABC2) > 1.45 the anti‐PbFCl‐type structure is found (Q(ABC2) = Vm(A2C2)/Vm(B2C2) with Vm(A2C2) > Vm(B2C2); Vm: molar volume, A, B = alkali metals).  相似文献   

10.
The reaction of bis(N-salicylidene)dicarboxylic acid dihydrazides (H4 Lig) with cobalt(II) salts was investigated. Chelates of the types Co(H3 Lig)X ·nH2O, Co2(H2 Lig)X 2, Co3(H3 Lig)2 X 4, Co(H2 Lig) ·nH2O and Co(H3 Lig)2 ·nH2O (X=Cl, Br, I or SCN) were isolated and characterized by their infrared and electronic spectra as well as their magnetic properties.
Koordinationsverbindungen von Hydrazinderivaten mit Übergangsmetallen, 23. Mitt.: Kobalt(II)-Chelate von Bis(N-salicyliden)dicarbonsäuredihydraziden
Zusammenfassung Die Reaktion von Bis(N-salicyliden)dicarbonsäuredihydraziden (H4 Lig) mit Kobalt(II)-Salzen ergab Chelate vom Typ Co(H3 Lig)X ·nH2O, Co2(H2 Lig)X 2, Co3(H3 Lig)2 X 4, Co(H2 Lig) ·nH2O and Co(H3 Lig)2 ·nH2O (X=Cl, Br, I oder SCN). Die Charakterisierung erfolgte mittels IR, Elektronenspektren und magnetischer Eigenschaften.
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11.
In this paper, the NO-to-NO 2 conversion in various gaseous mixtures is experimentally investigated. Streamer coronas are produced with a dc-superimposed high-frequency ac power supply (10–60 kHz). According to NO x removal experiments in N 2 +NO x and N 2 +O 2 +NO x gaseous mixtures, it is supposed that the reverse reaction NO 2 +ONO+O 2 may not only limit NO 2 production in N 2 +NO x mixtures, but also increase the energy cost for NO removal. Oxygen could significantly suppress reduction reactions and enhance oxidation processes. The reduction reactions, such as N+NON 2 +O, induce negligible NO removal provided the O 2 concentration is larger than 3.6%. With adding H 2 O into the reactor, the produced NO 2 per unit removed NO can be significantly reduced due to NO 2 oxidation. NH 3 injection could also significantly decrease the produced NO 2 via NH and NH 2 - related reduction reactions. Almost 100% of NO 2 can be removed in gaseous mixtures of N 2 +O 2 +H 2 O+NO 2 with negligible NO production.  相似文献   

12.
11 and 12 molar reactions of dioxouranium(VI) acetate dihydrate with the monobasic bidentateSchiff bases,o-HOC6H4CH=NR oro-HOC10H6CH=NR (R=C2H5,n-C3H7,n-C4H9 or C6H5) and bibasic tridentateSchiff bases,o-HOC6H4CH=NR(OH) oro-HOC10H6CH=NR(OH) (R=–CH2CH(CH3)- or —CH2CH2CH2–) have been studied and derivates of the type UO2(OAc)2(SBH), UO2(OAc)2(SBH)2, UO2(OAc)2(SBH 2) and UO2(OAc)2(SBH 2)2 (whereSBH andSBH 2 represent monobasic bidentate and bibasic tridentateSchiff base molecules respectively) have been isolated. These have been characterized by elemental analysis, conductance measurements and IR spectral studies.
UO2 2+-Komplexe von Schiff-Basen. VII. Uranylacetat-Komplexe mit monobasischen zweizähnigen und bibasischen dreizähnigen Schiff-Basen
Zusammenfassung Es wurden in 1:1- und 1:2-molaren Reaktionen von UO2(OAc)2·2H2O mitSchiff-Basen (L) Komplexe des Typs UO2(OAc)2 L bzw. UO2(OAc)2 L 2 isoliert. Die Komplexe wurden mittels Elementaranalyse, Leitfähigkeitsmessungen und IR-Spektren untersucht.
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13.
The glass transition temperature Tg of nylon 6 decreases monotonically toward a finite value Tgl upon increase of the moisture content. The mechanism of this decrease entails the reversible replacement of intercaternary hydrogen bonds in the accessible regions of the polyamide. The limiting glass transition temperature Tgl is approached when the moisture content approaches Wl, which corresponds to the amount of water required for complete interaction with all accessible amide groups. Denoting with Tg0 the glass transition temperature of the dry polymer, the effect of water on Tg is represented by the equation, Tg = (ΔTg)0 exp{?[ln(ΔTg)0]W/τWl} + Tgl, where (ΔTg)0 = Tg0 ?Tgl, and τ = W(Tgl+1)/Wl. This equation appears to be generally applicable to hydrophilic polymers, since correspondingly calculated data are also in very good agreement with experimental data for polymers such as nylon 66, poly(vinyl alcohol), and polyN-vinylpyrrolidone. The effect of water of Young's modulus E of nylon 6 is represented by an analogous relationship, and the quantity In[(E?El)/(Tg?Tgl)] is a linear function of the moisture content.  相似文献   

14.
Positron annihilation lifetime measurements are reported for four monodisperse polystyrenes with molar mass M = 4,000, 9,200, 25,000, and 400,000. The temperature dependences of orthopositronium (o-Ps) lifetime (τ3) and intensity (I3) were measured from 5°C to Tg + 30°C for each sample. From these data, the free volume hole size, 〈vf(τ3)〉, and fractional free volume hps=CI3〈vf(τ3)〉 were calculated. The temperature dependences of τ3, 〈vf(τ3)〉 and hps show a discrete change in slope at an effective glass transition temperature, Tg,ps, which is measurably below the conventional bulk Tg. This suggests that τ3 is sensitive to large holes which retain their liquid-like mobility in the glassy state. Good agreement was found for T > hg,ps between hps and the theoretical free volume fraction hth deduced from experimental P-V-T data for polystyrene using the statistical mechanical theory of Simha and Somcynsky. Below Tg,ps, deviations between hps and hth are observed, hps falling increasingly below hth as temperature decreases. Whereas hps and hth depend strongly on M in the melt, each essentially independent of M in the glass. A free volume quantity, computed from the bulk volume, which is in good numerical agreement with the Simha-Somcynsky h-function in the melt, gives improved agreement with hps in the glassy state. © 1994 John Wiley & Sons, Inc.  相似文献   

15.
Some aminophosphine oxides (AmPOs), (R 1)(R 2)(R 3)P=O [R 1?=?R 2?=?R 3?=?HNCH2CH=CH2; R 1?=?R 2?=?Ph, R 3?=?HNCH2CH=CH2; R 1?=?R 2?=?R 3?=?HNNMe2; R 1?=?R 2?=?Ph, R 3?=?HNNMe2; R 1?=?R 2?=?R 3?=?NC4H8O; R 1?=?R 2=Ph, R 3?=?NC4H8O], have been synthesized. The coordination chemistry of these AmPOs is studied with La(III), Th(IV), and U(VI) salts. The products are characterized by various analytical and spectroscopic techniques, and the thermal properties of the ligands and their complexes examined. The TGA data for these compounds show different decomposition temperatures, as well as thermal stability of the metal complexes. Comparisons are made among different ligands on their selective complexing ability towards some chosen metal salts. Mulliken population analysis shows that the basicity of P=O of ligand increases with an increase in the number of P-bonded amino groups.  相似文献   

16.
The formation of cluster orbitals in CsSn2Br5 is discussed and related more generally to tetragonal compounds of the type AB2X5 (A=monovalent cation; B=Sn, Pb; X=Cl, Br, I). The crystal structures of CsSn2Cl5 and CsSn2Br5 have been solved by single-crystal X-ray diffraction. These compounds are isostructural with each other and a range of AB2X5 structural analogues. In many AB2X5 compounds where B is a subvalent main group metal a tetragonal cell is observed with space group I4/mcm. The structures of CsSn2Br5 and CsSn2Cl5 are layered with polymeric sheets of [Sn2X5]n−n separated by the Cs+ cations. Stereochemical considerations suggest that stabilization of this structural form, rather than the more ionic NH4Pb2Cl5 or NaSn2Cl5 structures, is through interaction of the “nonbonding” valence electron pairs on tin with low-lying empty d-orbitals on neighboring X atoms. Electronic structure calculations based on the structural data confirm the likelihood of cluster orbital formation. Crystal data: CsSn2Cl5, tetragonal, I4/mcm, a=8.153(1) Å, c=14.882(4) Å, Z=4, R1=0.0215, wR2=0.0503 [I>2σ(I)], R1=0.0393, wR2=0.0536 (all data); CsSn2Br5, tetragonal, I4/mcm, a=8.483(6) Å, c=15.28(2) Å, Z=4, R1=0.0607, wR2=0.1411 [(I>2σ(I)], R1=0.1579, wR2=0.1677 (all data).  相似文献   

17.
荧光材料基质的结构调制对于调控发光材料的发光性能,探索固体结构-性能关系具有重要的研究意义。本文以Y2SiO5基质为模型,分别利用Si/Al和Si/P取代,以[AlO4]和[PO4]四面体替换[SiO4]四面体,设计合成了一系列组成为Y1.95Si1-xAlxO5-xFx∶0.05Ce3+(x=0.05,x=0.1,x=0.2,x=0.4,x=1)和Y1.95-yCaySi1-yPyO5∶0.05Ce3+(y=0,y=0.02,y=0.04,y=0.06,y=0.08,y=0.2)的荧光材料。结合X射线衍射、荧光光谱、荧光寿命等测试手段对其进行了表征分析。结果表明,在x≤0.2,y≤0.04时得到的产物能够保持Y2SiO5的结构特征,在一定的基质组成替换范围内,设计合成的样品Y1.95Si1-xAlxO5-xFx∶0.05Ce3+、Y1.95-yCaySi1-yPyO5∶0.05Ce3+能提高发光强度,发射光谱呈现蓝移现象。荧光寿命测试表明这两个系列的化合物中Ce3+所处的基质环境变化较小,Ce3+发光也未产生较大的变化。  相似文献   

18.
Summary The infrared and Raman spectra ofPh 3SiSiH3,Ph 3SiSiD3,Ph 2HSiSiHPh 2,Ph 2DSiSiDPh 2,PhH2SiSiH2 Ph andPhD2SiSiD2 Ph are reported and assigned with the aid of a normal coordinate analysis (NCA). The syntheses and vibrational spectra of thep-tolyldisilanespTol 3SiSiH3, andpTolH2SiSiH2 pTol are described, too.
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19.
A modification of a variation principle due to Delves, is derived which permits the direct calculation of energy differences between states of two different Hamiltonians: [Δ ??] = 〈X0| ??x – Wx|X1〉 – 〈Y0|??y – Wy|y1〉 + 〈X0| Δ ??|Y0〉 · 〈X0| Y0〉?1. Δ ?? = ??y – ??x, |X0〉 and |Y0〉 are the wave functions for the X and Y states and |X1〉 and |Y1〉 are functions defined in the text. The principle is applied to a few simple examples.  相似文献   

20.
Summary.  The optical absorption, photoluminescence, and photoconductivity spectra of some compounds of the formulas [R(CH2) n NH3] x M y X z , [R(CH2) n NH(CH3)2] x M y X z , [R(CH2) n S(CH3)2] x M y X z , [R(CH2) n SC(NH2)2] x M y X z , and [R(CH2) n SeC(NH2)2] x M y X z (R = organic residue; M = Bi(III), Pb(II), Sn(II), Cu(I), Ag(I) etc; X = I, Br, Cl; n, x, y, z = 0, 1, 2, 3, …) are briefly reviewed, and some new results are reported. The position, intensity, and shape of the excitonic bands depend on the dimensionality and size of the inorganic network as well as on the nature of the M, X, R, and onium moieties. Received June 23, 2000. Accepted August 1, 2000  相似文献   

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