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1.
Nest-shaped cluster [MoOICu 3S 3(2,2′-bipy) 2] (1) was synthesized by the treatment of (NH 4) 2MoS 4, CuI, ( n-Bu) 4NI, and 2,2′-bipyridine (2,2′-bipy) through a solid-state reaction. It crystallizes in monoclinic space group P2 1/ n, a=9.591(2) Å, b=14.820(3) Å, c=17.951(4) Å, β=91.98(2)°, V=2549.9(10) Å 3, and Z=4. The nest-shaped cluster was obtained for the first time with a neutral skeleton containing 2,2′-bipy ligand. The non-linear optical (NLO) property of [MoOICu 3S 3(2,2′-bipy) 2] in DMF solution was measured by using a Z-scan technique with 15 ns and 532 nm laser pulses. The cluster has large third-order NLO absorption and the third-order NLO refraction, its 2 and n2 values were calculated as 6.2×10 −10 and −3.8×10 −17 m 2 W −1 in a 3.7×10 −4 M DMF solution. 相似文献
2.
Binuclear complexes [{Cu(NN)(PhNHpy)} 2(μ-OH) 2](PF 6) 2, where NN=2,2′-bipyridine (bipy) or 1,10-phenanthroline (phen), have been synthesized and characterized by chemical analysis, conductance measurements and IR and electronic spectroscopy. The X-ray crystal structure of [{Cu(bipy)(PhNHpy)} 2(μ-OH) 2](PF 6) 2 shows a distorted square-planar pyramidal coordination for Cu(II), defined by two nitrogen atoms of bipy, two bridging oxygen atoms and the pyridinic nitrogen atom of the ligand. Magnetic susceptibility measurements (in the 4.8–290 K range) reveal coupling which is antiferromagnetic for the bipy complex (2 J=−24.2 cm −1) and slightly ferromagnetic for the phen complex (2 J=3.3 cm −1). The EPR spectra show the expected triplet signals. 相似文献
3.
The reaction of an ethanolic solution of copper(II) pyridinecarboxylates CuX 2· nH 2O (where X is nicotinate (nic) ( n=0) or isonicotinate (isonic) ( n=4)) with ethylenediamine (en) in a molar ratio of 1:2 lead to the isolation of solid tetragonally distorted octahedral complexes of the type [Cu(en) 2(H 2O) 2]X 2· nH 2O ( n=1 for nic; n=0 for isonic). The analogous reaction of CuX 2· nH 2O with diethylenetriamine (dien) in a molar ratio of 1:1 leads to the formation of square-pyramidal pentacoordinated complexes of the type [CuX(dien)(H 2O)]X. On the other hand, the reaction of equimolar quantities of copper(II) nitrate and dien with nicotinate anions (equimolar quantities of pyridinecarboxylic acid and NaOH) in ethanolic solutions gives a solid monomeric complex [Cu(nic)(NO 3)dien)(H 2O)]·H 2O in which the coordination polyhedron around the Cu(II) atom is a (4+1+1) distorted tetragonal bipyramid. Based on the molecular structure the electronic and IR spectra are discussed. Moreover, the results of the quantitative determination of antimicrobial activity of the isonic complexes [Cu(isonic) 2(H 2O) 4], [Cu(en) 2(H 2O) 2](isonic) 2, [Cu(isonic)(dien)(H 2O)](isonic), as well as isonicotinic acid, ethylenediamine and diethylenetriamine alone are discussed. 相似文献
4.
The complexes Zn(bipy)Cl 2 and Zn(bipy) 2Cl 2 as well as 2,2′-bipyridyl in aqueous solution (D 2O) have been examined by the NMR method. The presence of the monocationic bipy D + form in aqueous bipyridyl solution has been found. The changes of chemical shifts of bipyridyl protons for complexes Zn(bipy) 3Cl 2 and Zn(bipy)Cl 2 have confirmed explicitly the essential influence of diamagnetic currents on the NMR spectrum of Zn(bipy) 3Cl 2. The comparison of the spectra of 2,2′-bipyridyl (in CH 3OH) and of Zn(bipy)Cl 2 may also suggest the presence of the nonbonding metal-proton 6 interaction. 相似文献
5.
A new family of heteropolytungstate complexes (NH 4) 21[Ln(H 2O) 5{Ni(H 2O)} 2As 4W 40O 140]· xH 2O(Ln=Y, Ce, Pr, Nd, Sm, Eu, Gd) were prepared by the reaction of Na 27[NaAs 4W 40O 140]·60H 2O with NiCl 2·6H 2O and Ln(NO 3) 3· xH 2O at pH≈4.5. The crystal structures of (NH 4) 21[Gd(H 2O) 5{Ni(H 2O)} 2As 4W 40O 140]·51H 2O was determined by X-ray diffraction analysis and element analysis. The compound crystallizes in the monoclinic space group P2 1/ n with a=19.754(3), b=24.298(4), c=39.350(6) Å, β=100.612(3)°, V=18564(5) Å 3, Z=2, R1( wR2)=0.0544(0.0691). The central site S1 and two opposite sites S2 of the big cyclic ligand [As 4W 40O 140] 28− are occupied by one Ln 3+and two Ni 2+, respectively, each site supply four O d coordinating to metal ion, another one water molecule and other five water molecules coordinate, respectively, to Ni 2+and Ln 3+. Polyanion [Ln(H 2O) 5{Ni(H 2O)} 2As 4W 40O 140] 21− has C2v symmetry. IR and UV–vis spectra of [NaAs 4W 40O 140] 27− of the title compounds are discussed. 相似文献
6.
A novel tetranuclear terbium(III) complex [Tb 4(OH) 4(pybet) 6(H 2O) 8][Tb 4(OH) 4(pybet) 6(H 2O) 7 (NO 3)](ClO 4) 14·6H 2O has been synthesized and shown by X-ray crystallography to have a cubane-like Tb 4(μ 3-OH) 4(μ 2-carboxylato-O,O′) 6 core. The ligand pybet is pyridinoacetate, C 5H 5+N-CH 2CO 2−. Magnetic susceptibility data were measured for this Tb 4 complex in the range of 2.0–320 K and in fields of 1.0 G to 50.0 kG. It is concluded that either there is very weak antiferromagnetic exchange interaction ( J = −0.015 cm −1) or there is a small crystal-field splitting of the 7F 6 Tb III ground state. 相似文献
7.
By use of the three-layer diffusion method, reactions of flexible bipyridyl ligands (4,4′-bpp or 3,3′-bpp) with M(II) salts (M = Zn, Cd) and multi-carboxylate ligands resulted in the formation of four interesting d 10 metal–organic coordination polymers: [Zn(μ-4,4′-bpp)Br 2] n (1), [Zn(μ-4,4′-bpp)(1,2-bdc)] n · nH 2O (2), [Zn(μ-3,3′-bpp)(1,3-bdc)] n · nCH 3OH · 2 nH 2O (3) and [Cd(μ-3,3′-bpp)(C 4H 2O 4)] n · 3 nH 2O (4) (4,4′-bpp = 2,2′-bis(4-pyridylmethyleneoxy)-1,1′-biphenylene; 3,3′-bpp = 2,2 ′-bis(3-pyridylmethyleneoxy)-1,1′-biphenylene; bdc=benzenedicarboxylate, C 4H 4O 4 = fumaric acid). Complex 1 has a 2D sheet structure consisting of two unusual zigzag Zn(II) chains which are nearly perpendicular to each other. Complex 2 is comprised of two-leg ladders, in which [Zn(4,4′-bpp)] chains serve as the side rails and 1,2-bdc ligands serve as the cross rungs. In complex 3, every two 1,3-bdc ligands connect the neighbouring Zn(II)-3,3′-bpp dimetallic rings in η 1 coordination modes into an interesting chain structure. Complex 4 consists of an anionic macrocycle-containing cadmium dicarboxylate sheets that are separated by 3,3′-bpp. These d 10 metal complexes exhibit high thermal stabilities and strong luminescence efficiencies. 相似文献
8.
A series of novel heterobimetallic crown ether-like polyoxadiphosphaplatinaferrocenophanes cis-[1,1′-Fc(CH 2O(CH 2CH 2O) nCH 2CH 2PPh 2) 2]PtCl 2 ( n=1–3) (4a–c) was synthesized in good yield by cyclization of the bis(phosphine) ligands 1,1′-Fc(CH 2O(CH 2CH 2O) nCH 2CH 2PPh 2) 2 ( n=1–3) (3a–c) and (PhCN) 2PtCl 2 under high dilution conditions in CH 2Cl 2. The bisphosphines 3a–c are obtained by reaction of the corresponding diols 1,1′-Fc(CH 2O(CH 2CH 2O) nCH 2CH 2OH) 2 ( n=1–3) (1a–c) with: (i) CH 3SO 2Cl in CH 2Cl 2 and (ii) LiPPh 2 in THF. Although the X-ray crystal structure of 4a shows that the cavity is large enough for the encapsulation of small metal cations, inclusion experiments of 4a–c with Group 1 cations, and Mg 2+, or NH 4+ in solution applying NMR titration and cyclovoltammetric methods reveal no evidence for the formation of host–guest complexes for 4a,b. In the case of 4c only the addition of Na + or K + leads to an insignificant effect. 相似文献
9.
A series of chromium(III) complexes [Cr(bipy)(HC 2O 4) 2]Cl·3H 2O (1), [Cr(phen)(HC 2O 4) 2]Cl·3H 2O (2), [Cr(phen) 2(C 2O 4)]ClO 4 (3), [Cr 2(bipy) 4(C 2O 4)](SO 4)·(bipy) 0.5·H 2O (4) and [Mn(phen) 2(H 2O) 2] 2[Cr(phen)(C 2O 4) 2] 3ClO 4·14H 2O (5) were synthesized (bipy=4,4′-bipyridine, phen=1,10-phenanthroline), while the crystal structures of 1 and 3–5 have been determined by X-ray analysis. 1 and 3 are mononuclear complexes, 4 contains binuclear chromium(III) ions and 5 is a 3D supromolecule formed by complicated hydrogen bonding. 1–3 are potential molecular bricks of chromium(III) building blocks for synthesis heterometallic complexes. When we use these molecular bricks as ligands to react with other metal salts, unexpected complexes 4 and 5 are isolated in water solution. The synthesis conditions and reaction results are also discussed. 相似文献
10.
The calcium phosphate which corresponds to the formula Ca 3(PO) 4 · nH 2O (2< n<3) was isolated from solutions with Ca/P molar ratio 0.2 and pH 7. The compound was characterised by chemical and thermogravimetric analyses, Fourier-transform infrared (FTIR) spectroscopy and X-ray diffraction. The FTIR spectra were compared with spectra of β-tricalcium phosphate (β-TCP) in the atlases for analysis of urinary calculi and other literature data. 相似文献
11.
Reactions of CoX 2·6H 2O (X = Cl −, ClO 4−) with bis(3,5-dimethylpyrazolyl)methane (dmpzm) and formic acid, acetic acid, benzoic acid, salicylic acid, maleic acid, or fumaric acid under the presence of KOH solution produced a new family of Co(II)/dmpzm complexes, [Co(dmpzm) 2L]X· nH 2O (1: L = O 2CH, X = Cl, n = 2; 2: L = OAc, X = Cl, n = 3; 3: L = benzoate, X = ClO 4, n = 1/3; 4: L = salicylate, X = ClO 4, n = 1/3) and [Co 2(dmpzm) 4L](ClO 4) 2· nSolv (5: L = maleate, n = 3, Solv = H 2O; 6: L = fumarate, n = 2, Solv = MeOH). These compounds were structurally characterized by elemental analysis, IR spectroscopy, and single-crystal X-ray diffraction. Compounds 1–4 are mononuclear while 5–6 are binuclear. Each cobalt atom of 1–6 is hexacoordinate, with a distorted octahedral CoN 4O 2 coordination geometry incorporating two N, N′-bidentate dmpzm ligands and one O, O′-bidentate carboxylate ligand. There are rich intra- and intermolecular hydrogen bonds in the crystals of 1–6, thereby forming either 2D hydrogen-bonded networks (1 and 2) or 3D hydrogen-bonded networks (3–6). In addition, the thermal behaviors of 1–6 were also investigated. 相似文献
12.
The enthalpies of dissolution in water of new ternary complexes of four late trivalent lanthanide ions Ln(Gly) 4Im(ClO 4) 3· nH 2O (Ln=Gd, Tb, Dy, Y; Gly: glycine; Im: imidazole and n=1 or 2) were measured by means of a Calvet microcalorimeter. Empirical formulae for the calculation of the enthalpies of dissolution (Δ dissH), relative apparent molar enthalpies (Δ dissH (app)), relative partial molar enthalpies (Δ dissH (partial)) and enthalpies of dilution (Δ dilH1,2) were obtained from the experimental data of the enthalpies of dissolution of these complexes. The plot of Δ dissHmΘ, Δ dissH (app) and Δ dissH (partial) versus the values of the ionic radius of the lanthanide element ( r) showed a grouping effect of the lanthanide elements, indicating that the coordinated bond between the lanthanide ions and the ligands has some covalent character. The unknown value of the standard enthalpy of dissolution for the similar complex: Ho(Gly) 4Im(ClO 4) 3·H 2O was estimated according to the plot of Δ dissHmΘ versus r. 相似文献
13.
139La-NMR chemical shifts were measured for several anionic complexes of formulae Li(C 4H 8O 2) 3/2 [La(ν 3-C 3H 5) 4], [Li(C 4H 8O 2) 2][Cp′ nLa(ν 3-C 3]H 5) 4−n] (Cp′ = Cp(ν 5-C 5H 5); n = 1, 2 and Cp′ = Cp * (ν 5-C 5Me5); N = 1) and Li[R nLa(ν 3-C 3H 4) 4− n] (R = N(SiMe 3) 2; n = 1, 2 and R = CCsIMe 3; n = 4), as well as for neutral compounds for formulae La(ν 3-C 3H 5) 3L n (L = (C 4H 8O 2) 1.5, (HMPT) 2, TMED), Cp′ nLa(ν 3-C 3H 5) 3−n (Cp′= Cp(ν 5-Cp 5H 5), Cp *(ν 5-C 5Me 5); n = 1, 2) and La(ν 3-C 3H 2) 2X(THF) 2 X = Cl, Br, I). Typical ranges of the 139La-NMR chemical shifts were found for the different types of complex independent of number and kind of organyl groups directly bonded to lanthanum. Zusammenfassung139La-NMR-Spektroskopie wurde an einer Reihe anionischer Allyllanthanat(III)-Komplexe der Zusammensetzung
]- [La)ν3-C3H5)4, [Li(C4H8)2][Cp′nLa(ν3-C3H5)4−n(Cp′ = Cp(ν5-C5H5); n = 1, 2 und Cp′ = Cp * (ν5-C5Me5); N = 1) und Li[RnLa(ν3-C3H5)4−n (R = B(SiMe3)2; n = 1, 2 und R = CCSiMe3; n = 4 sowie neutraler Allyllanthan(III)-Komplexe der Zusammensetzung La(ν3-C3H5)3Ln (Ln = (C4H8O2)1.5, (HMPT)2, TMED), Cp′n, La(ν3-C3H5)3−n (Cp′ = Cp(ν5-C5H5), Cp * (ν5- Cp5Me5); n = 1, 2) und La(ν3-Cp3H5)2X(THF)2 (X = Cl, Br, I) durchgefürt. In Abhängikeit von der Anzahl und der Art der am Lanthan gebundenen Gruppen wurden für die verschieden Komplextypen charakteristische Resonanzbereiche ermittelt. 相似文献
14.
The reactions of MnRe(CO) 10 with As 2(CF 3) 4 and MnCo(CO) 9 with P 2(CF 3) 4, As 2(CF 3) 4, S 2(CF 3) 2, Se 2(CF 3) 2, (CF 3) 2EI (E = P, As), (CF 3) 2AsH, (CF 3) 2AsE′CF 3 (E′ = S, Se), (CF 3) 2PSeCF 3, Me 2AsI and (CF 3) 2PPMe 2, respectively, have been studied under various conditions. Besides already known mono- and binuclear compounds the heteronuclear complexes MnRe(CO) 8[As(CF 3) 2] 2 and MnCo(CO) 7[E(CF 3) 2] 2 (E = P, As) are formed. The reactions proceed via cleavage of the M---M′ bond and formation of the mononuclear species Mn(CO) 5X and M′(CO) nY (M′ = Re, n = 5; M′ = Co, n = 4). 相似文献
15.
The neutral nitrogen-bidentate ligand, diphenylbis(3,5-dimethylpyrazol-1-yl)methane, Ph 2CPz′ 2, can readily be obtained by the reaction of Ph 2CCl 2 with excess HPz′ in a mixed-solvent system of toluene and triethylamine. It reacts with [Mo(CO) 6] in 1,2-dimethoxyethane to give the η 2-arene complex, [Mo(Ph 2CPz′ 2)(CO) 3] (1). This η 2-ligation appears to stabilize the coordination of Ph 2CPz′ 2 in forming [Mo(Ph 2CPz′ 2)(CO) 2(N 2C 6H 4NO 2- p)][BPh 4] (2) and [Mo(Ph 2CPz′ 2)(CO) 2(N 2Ph)] [BF 4] (3) from the reaction of 1 with the appropriate diazonium salt but the stabilization seems not strong enough when [Mo{P(OMe) 3} 3(CO) 3] is formed from the reaction of 1 with P(OMe) 3. The solid-state structures of 1 and 3 have been determined by X-ray crystallography: 1-CH 2Cl 2, monoclinic, P2 1/ n, a = 11.814(3), b = 11.7929(12), c = 19.46 0(6) Å, β = 95.605(24)°, V = 2698.2(11) Å 3, Z = 4, Dcalc = 1.530 g/cm 3 , R = 0.044, Rw = 0.036 based on 3218 reflections with I > 2σ( I); 2 (3)-1/2 hexane-1/2 CH 3OH-1/2 H 2O-1 CH 2Cl 2, monoclinic, C2/ c, a = 41.766(10), b = 20.518(4), c = 16.784(3) Å, β = 101.871(18)°, V = 14076(5) Å 3, Z = 8, Dcalc = 1.457 g/cm 3, R = 0.064, Rw = 0.059 based on 5865 reflections with I > 2σ( I). Two independent cations were found in the asymmetric unit of the crystals of 3. The average distance between the Mo and the two η 2-ligated carbon atoms is 2.574 Å in 1 and 2.581 and 2.608 Å in 3. The unfavourable disposition of the η 2-phenyl group with respect to the metal centre in 3 and the rigidity of the η 2-arene ligation excludes the possibility of any appreciable agostic C---H → Mo interaction. 相似文献
16.
The chiral bis-imine (1 R,2 R)-C 6H 10-[ E---N=CH---C 6H 3---3,4-(OMe) 2] 2 1 (LH) reacts with [Pd(OAc) 2] (1:1 molar ratio; OAc=acetate) giving the orthometallated [Pd(OAc)( C6H 2---4,5-(OMe) 2---2-CH= N-(1 R,2 R)-C 6H 10--- N=CH---C 6H 3-3′,4′-(OMe) 2-κ-C,N,N)] 2 (abbreviated as [Pd(OAc)(L-κ-C,N,N)]), through C---H bond activation on only one of the aryl rings and N, N-coordination of the two iminic N atoms. 2 reacts with an excess of LiCl to give [Pd(Cl)(L-κ-C,N,N)] 3. The reaction of 3 with AgClO 4 and neutral or anionic ligands L′ (1:1:1 molar ratio) affords [Pd(L-κ-C,N,N)(L′)](ClO 4) (L′=PPh 3 4a, NCMe 5, pyridine 6, p-nitroaniline 7) or [Pd(I)(L-κ-C,N,N)] 8. Complex 4a reacts with wet CDCl 3 giving [Pd( C6H 2---4,5-(OMe) 2---2-CH= N-(1 R,2 R)---C 6H 10--- NH 2-κ-C,N,N)(PPh 3)](ClO 4) 4b as a result of the hydrolysis of the C=N bond not involved in the orthometallated ring. The molecular structure of 4b·CH 2Cl 2 has been determined by X-ray diffraction methods. Cleavage of the Pd---N bond trans to the C aryl atom can be accomplished by coordination of strongly chelating ligands, such as acetylacetonate (acac) or bis(diphenylphosphino)ethane (dppe), forming [Pd(acac- O, O′)(L-κ-C,N)] 9 and [Pd(L-κ-C,N)(dppe-P,P′)](ClO 4) 12, while classical N, N′-chelating ligands such as 1,10-phenantroline (phen) or 2,2′-bipyridyl (bipy) behave as monodentate N-donor ligands yielding [Pd(L-κ-C,N,N)(κ 1-N-phen)](ClO 4) 10 and [Pd(L-κ-C,N,N)(κ 1-N-bipy)](ClO 4) 11. Treatment of 1 with PtCl 2(DMSO) 2 (1:1 molar ratio) in refluxing 2-methoxyethanol gives Cl 2Pt[( NH 2) 2C 6H 10---N,N′] 13a and [Pt(Cl)( C6H 2---4,5-(OMe) 2---2-CH= N-(1 R,2 R)---C 6H 10--- NH 2-κ-C,N,N)] 13b, while [Pt(Cl)(L-κ-C,N,N)] 14 can be obtained by reaction of [Pt(μ-Cl)(η 3-2-Me---C 3H 4)] 2 with 1 in refluxing CHCl 3. Complexes 2 and 3 catalyzed the arylation of methyl acrylate giving good yields of the corresponding methyl cinnamates and TON up to 847 000. Complex 3 also catalyzes the hydroarylation of 2-norbornene, but with lower yields and without enantioselectivity. 相似文献
17.
Lamellar crystalline calcium phenylphosphonate, as anhydrous Ca(HO 3PC 6H 5) 2 and hydrated Ca(HO 3PC 6H 5) 2·2H 2O compounds, were used as hosts for intercalation of polar n-alkylmonoamine molecules of the general formula CH 3(CH 2) nNH 2 ( n=0–4, 7) in water or 1,2-dichloroethane. An increase in the interlayer distance was observed. The exothermic enthalpic values for intercalation increased with the number of carbon atoms and with increasing concentration of the amines. The intercalation followed by a titration procedure in the solid/liquid interface with Ca(HO 3PC 6H 5) 2·2H 2O and Ca(HO 3PC 6H 5) 2 gave the enthalpy/number of carbons correlations: Δ intH=−(1.74±0.43)–(1.30±0.13) nc and Δ intH=−(4.15±0.15)–(1.07±0.03) nc, for water and 1,2-dichloroethane, respectively. A similar correlation Δ intH=−(4.27±0.80)–(1.85±0.21) nc was obtained in water by using the ampoule breaking procedure for Ca(HO 3PC 6H 5) 2·2H 2O. The increase in exothermic enthalpic values with the increase in n-aliphatic carbon atoms is more pronounced for the anhydrous compound and also when using the ampoule breaking procedure. The Gibbs free energies are negative. Positive entropic values favor intercalation in these systems. 相似文献
18.
The synthesis and reactivity of {(η 5-C 5H 4SiMe 3) 2Ti(CCSiMe 3) 2} MCl 2 (M = Fe: 3a; M = Co: 3b; M = Ni: 3c) is described. The complexes 3 are accessible by the reaction of (η 5-C 5H 4SiMe 3) 2Ti(CSiMe 3) 2 (1) with equimolar amounts of MCl 2 (2) (M = Fe, Co, Ni). 3a reacts with the organic chelat ligands 2,2′-dipyridyl (dipy) (4a) or 1,10-phenanthroline (phen) (4b) in THF at 25°C to afford in quantitative yields (η 5-C 5H 4SiMe 3) 2Ti(CSiMe 3) 2 (1) and [Fe(dipy) 2]Cl 2 (5a) or [Fe(phen) 2]Cl 2 (5b). 1/ n[Cu IHal] n (6) or 1/ n[Ag IHal] n (7) (Hal = Cl, Br) react with {(η 5 -C 5H 4SiMe 3) 2Ti(CCSiMe 3) 2}FeCl 2 (3a), by replacement of the FeCl 2 building block in 3a, to yield the compounds {(η 5-C 5H 4SiMe 3) 2Ti(C CSiMe 3) 2}Cu IHal (8) or {(η 5-C 5H 4SiMe 3) 2Ti(CSiMe 3) 2}Ag IHal (9) (Hal = Cl, Br), respectively. In 8 and 9 each of the two Me 3SiCC-units is η 2-coordinated to monomeric Cu I Hal or Ag IHal moieties. Compounds 8 and 9 can also be synthesized by the reaction of (η 5-C 5H 4SiMe 3) 2 Ti(CSiMe 3) 2 (1) with 1/ n[Cu IHal] n (6) or 1/ n [Ag IHal] n (7) in excellent yields. All new compounds have been characterized by analytical and spectroscopic data (IR, 1H-NMR, MS). The magnetic moments of compounds 3 were measured. 相似文献
19.
The photophysics of three complexes of the form Ru(bpy) 3−(pypm) 2+ (where bpy2,2′-bipyridine, pypm 2-(2′-pyridyl)pyrimidine and P=1, 2 or 3) was examined in H 2O, propylene carbonate, CH 3CN and 4:1 (v/v) C 2H 5OH---CH 3OH; comparison was made with the well-known photophysical behavior of Ru(bpy) 32+. The lifetimes of the luminescent metal-to-ligand charge transfer (MLCT) excited states were determined as a function of temperature (between −103 and 90 °C, depending on the solvent), from which were extracted the rate constants for radiative and non-radiative decay and Δ E, the energy gap between the MLCT and metal-centered (MC) excited states. The results indicate that *Ru(bpy) 2(pypm) 2+ decays via a higher lying MLCT state, whereas *Ru(pypm) 32+ and *Ru(pypm) 2(bpy) 2+ decay predominantly via the MC state. 相似文献
20.
The magnetic susceptibility of 1,1′,2,2′-tetramethylcobaltocene, Co[C 5H 3(CH 3) 2] 2, and 1,1′-diethylcobaltocene, Co(C 5H 4C 2H 5) 2, has been studied between 0.99 and 296 K. The data are well reproduced by a calculation of the dynamic Jahn-Teller effect for the 2E 1g(a 1g2e 2g4e 1g) ground state of D 5d symmetry. A suitable set of parameter values is given by ζ = 100 cm −1, δ = 150 cm −1, kJT = 0.40, κ = 0.70. The magnetism of cobaltocene, Co(C 5H 5) 2, may be described by parameter values of comparable magnitude. The results imply a significantly larger reduction of the spin-orbit coupling parameter ζ due to covalency than of the orbital reduction factor κ. 相似文献
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