共查询到20条相似文献,搜索用时 62 毫秒
1.
Several ruthenium(II) mono(acetylides) trans-[Cl(dppe) 2Ru---(CC) n---R] ( n=1–4; R=SiMe 3, H) and bis(acetylide) trans-[(dppe) 2Ru(---(CC) 2---R) 2] (R=SiMe 3, H) were selectively obtained and could be used as a new set of building blocks for rigid rod-like structures and further assemblies. Especially, the oxidative coupling of trans-[Cl(dppe) 2Ru---(CC) 3---H] with Cu(OAc) 2 led to the formation of the first Ruthenium(II) binuclear species with 12 carbon atoms between the remote metals. This compound shows two reversible redox processes. 相似文献
2.
The nitrosyl complexes trans-[ReCl(NO)(dppe) 2]A 2 (1; A = BF 4 or NO 3; dppe = Ph 2PCH 2CH 2−PPh 2) and trans-[ReCl(NO)(dppe) 2][BF 4] (2) have been prepared from the reactions of NO[BF 4] or NO with trans-[ReCl(N 2)dppe) 2]. An unusual facile oxidation of NO to nitrate is involved in the formation of (1, A = NO 3), the X-ray structure of which is reported. 相似文献
3.
The study of the reactivity of [Pt 2M 4(CCR) 8] (M=Ag or cu; R=Ph or tBu) towards different neutral and anionic ligands is reported. This study reveals that reactions of the phenylacetylide derivatives [Pt 2M 4(CCPh) 8] with anionic, X − (X=Cl or Br) or neutral donors (CN tBu or py) in a molar ratio 1:4 (m/donor ratio 1:1) yield the trinuclear anionic (NBu 4) 2[{Pt(CCPh) 4 (MX) 2] (M=Ag or Cu, X =Cl or Br) or neutral [{Pt(CCPh0 4=sAGL) 2] (L=CN tBu or py) complexes, respectively. The crystal structure of (NBu 4) 2[{Pt(CCPh) 4}(CuBr) 2](4) shows that the anion is formed by a dianionic Pt(CCPh) 4 fragment and two neutral CuBr units joined through bridging alkynyl ligands. All the alkynyl groups are σ bonded to Pt and η 2-coordinated to a Cu atom which have an approximately trigonal-planar geometry. By contrast, similar reactions with [Pt 2M 4(CC tBu) 8] (molar ratio M/donor 1:1) afford hexanuclear dianionic (NBu 4) 2[Pt 2M 4(CC tBu) 8X 2] or neutral [Pt 2Ag 4(CC tBu0 8Py 2]. Only by treatment with a large exces of Br − (molar ratio M/Br − 1:2) are the trinuclear complexes (NBu 4) 2[{Pt(CC tBu 4 (MBr) 2] (M=Ag, Cu) obtained. Attempted preparations of analogous complexes with phosphines (L′=PPh 3 or PEt 3) by reactions of [Pt 2M 4(CCR 8] with L′ leads to displacement of alkynyl ligands from platinum and formation of neutral mononuclear complexes [ trans-Pt(CCR) 2L′ 2]. 相似文献
4.
Activation volumes for aquation of cis-[Co(en) 2(NO 2)Cl] +, trans-[Co(en) 2 (CN)Cl] +, cis-- and cis-β-[Co(trien)Cl 2] + have been determined, and are compared with values reported for a range of chloroaminecobalt(III) complexes. Variation of reported Δ V≠ in terms of, particularly, solvation effects is discussed. 相似文献
5.
The new diphenolato complexes [{Mo(NO){HB(dmpz) 3}Cl} 2Q] where dmpz = 3,5-dimethylpyrazolyl and Q = OC 6H 4(C 6H 4O ( n = 1 or 2), OC 6H 4CR=CRC 6H 4O (R = H or Et), and OC 6H 4CH=CHC 6H 4CH=CHC 6H 4O have been prepared and their electrochemical properties (cyclic and differential pulse voltammetry) compared with previously reported analogues where Q = OC 6H 4O, OC 6H 4EC 6H 4O (E = SO 2, CO and S), OC 6H 4 (CO)C 6H 4 C 6H 4(CO)C 6H 4O and 1,5- and 2,7-O 2C 10H 6. The electrochemical interaction between the redox centres in the new complexes is very weak, in contrast to that in the 1,4-benzenediolato and naphthalendiolato species. The EPR spectra of the reduced mixed-valence species [{Mo(NO){HB(dmpz) 3}Cl} 2Q] − where Q = 1,3- and 1,4-OC 6H 4O and OC 6H 4SC 6H 4O shows that they are valence-trapped at room temperature, whereas those of the dianions [{Mo(NO){HB(dmpz) 3}Cl} 2Q] 2− where Q = 1,4-OC 6H 4O, OC 6H 4EC 6H 4O (E = CO or S) and OC 6H 4CH=CHC 6H 4CH=CHC 6H 4O shows that the unpaired spins on each molybdenum centre are strongly correlated ( J, the spin exchange integral A Mo, the metal-hyperfine coupling constant). The electrochemical properties and the comproportionation constants for the reaction [{Mo(NO){HB(dmpz) 3} Cl} 2Q] + [{Mo(NO){HB(dmpz) 3}Cl}O] 2] 2−2[{Mo(NO) {HB(dmpz) 3}Cl} 2Q] − where Q = diphenolato bridge, are compared with related compounds containing benzenediamido and dianilido bridges. 相似文献
6.
Reactions of [(η 6-arene)RuCl 2] 2 (1) (η 6-arene= p-cymene (1a), 1,3,5-Me 3C 6H 3 (1b), 1,2,3-Me 3C 6H 3 (1c) 1,2,3,4-Me 4C 6H 2(1d), 1,2,3,5-Me 4C 6H 2 (1e) and C 6Me 6 (1f)) or [Cp*MCl 2] 2 (M=Rh (2), Ir (3); Cp*=C 5Me 5) with 4-isocyanoazobenzene (RNC) and 4,4′-diisocyanoazobenzene (CN–R–NC) gave mononuclear and dinuclear complexes, [(η 6-arene)Ru(CNC 6H 4N=NC 6H 5)Cl 2] (4a–f), [Cp*M(CNC 6H 4N=NC 6H 5)Cl 2] (5: M=Rh; 6: M=Ir) , [{(η 6-arene)RuCl 2} 2{μ-CNC 6H 4N=NC 6H 4NC}] (8a–f) and [(Cp*MCl 2) 2(μ-CNC 6H 4N=NC 6H 4NC)}] (9: M=Rh; 10: M=Ir) , respectively. It was confirmed by X-ray analyses of 4a and 5 that these complexes have trans-forms for the ---N=N--- moieties. Reaction of [Cp*Rh(dppf)(MeCN)](PF 6) 2 (dppf=1,1′-bis (diphenylphosphino)ferrocene) with 4-isocyanoazobenzene gave [Cp*Rh(dppf)(CNC 6H 4N=NC 6H 5)](PF 6) 2 (7), confirmed by X-ray analysis. Complex 8b reacted with Ag(CF 3SO 3), giving a rectangular tetranuclear complex 11b, [{(η 6-1,3,5-Me 3C 6H 3)Ru(μ-Cl} 4(μ-CNC 6H 4N=NC 6H 4NC) 2](CF 3SO 3) 4 bridged by four Cl atoms and two μ-diisocyanoazobenzene ligands. Photochemical reactions of the ruthenium complexes (4 and 8) led to the decomposition of the complexes, whereas those of 5, 7, 9 and 10 underwent a trans-to- cis isomerization. In the electrochemical reactions the reductive waves about −1.50 V for 4 and −1.44 V for 8 are due to the reduction of azo group, [---N=N---]→[---N=N---] 2−. The irreversible oxidative waves at ca. 0.87 V for the 4 and at ca. 0.85 V for 8 came from the oxidation of Ru(II)→Ru(III). 相似文献
7.
The complexes [Fe{η-C 5H 4---( E)---CH=CH---4-C 6H 4CCX} 2] [X=SiMe 3 (1), H (2), Au(PCy 3) (3), Au(PPh 3) (4), Au(PMe 3) (5), RuCl(dppm) 2 (7), RuCl(dppe) 2 (8)] and [Fe{η-C 5H 4---( E)---CH=CH---4-C 6H 4CH=CRuCl(dppm) 2} 2](PF 6) 2 (6) have been prepared and the identities of 1 and 7 confirmed by single-crystal X-ray structural studies. Complexes 1–8 exhibit reversible oxidation waves in their cyclic voltammograms attributed to the Fe II/III couple of the ferrocenyl groups, 6–8 also showing reversible (7, 8) or non-reversible (6) processes attributed to Ru-centered oxidation. Cubic nonlinearities at 800 nm by the Z-scan method are low for 1–5; in contrast, complexes 6 and 7 exhibit large negative γreal and large γimag values. A factor of 4 difference in γ and two-photon absorption cross-section σ2 values for 6 and 7 suggest that they have potential as protically switchable NLO materials. 相似文献
8.
Reaction of cis-[Ptph 2(SMe 2) 2] with Me 2PCH 2PMe 2 (dmpm) gave cis-[PtPh 2(dmpm-P) 2] (1) or cis,cis-[Pt 2Ph 4(μ-dmpm) 2] (2) and reaction of 1 with [Pt 2Me 4(μ-SMe 2) 2] gave cis,cis-[Ph 2Pt(μ-dmpm) 2PtMe 2] (3). Reaction of 1 with trans-[PtClR(SMe 2) 2] gave cis, trans-[Ph 2Pt(μ-dmpm) 2PtClR], R = Me (5) or Ph (6), and in polar solvents, these isomerized to give [Ph 2Pt(μ-dmpm) 2PtR] +Cl −. When R = Me, further isomerization via the phenyl group transfer gave [PhMePt(μ-dmpm) 2PtPh] +Cl −. Oxidative addition of methyl iodide occurred reversibly at the cis-[PtMe 2P 2 unit of 3 to give cis, fac-[Ph 2Pt(μ-dmpm) 2PtIMe 3] but complex 2 failed to react with MeI. A comparison with similar known complexes of Ph 2PCH 2PPh 2 (dppm) is made and differences are attributed primarily to the lower steric hindrance of dmpm. 相似文献
9.
The preparation of a series of new square-planar and half-sandwich type carbenerhodium(I) complexes will be described. The key to success is the use of the bis(stibane)rhodium compound trans-[RhCl(C 2H 4)(Sb iPr 3) 2] as starting material from which in a stepwise manner the complexes trans-[RhCl(=CRR′)(Sb iPr 3) 2] (L = P iPr 3, As iPr 3, SbEt 3) and [C 5H 5Rh(=CCR′)L] (L = Sb iPr 3, P iPr 3, PMe 3, CO, CN tBu) have been obtained. Displacement of the carbene ligand in either trans-[RhCl(=CPH 2)L 2]L = Sb iPr 3, P iPr 3 or [C 5H 5Rh(=CPh 2)(P iPr 3)] by CO or CN tBu leads to the formation of the corresponding carbonyl- or isocyanidrhodium compounds and the C---C coupling products Ph 2C=C=O and Ph 2C=C=N tBu, respectively. The carbene ligand is also involved in the selective formation of the isomeric olefins CH 2=CHCPh 2H and Ph 2C=CHCH 3 on treatment of trans-[RhCl(=CPh 2)(Sb iPr 3) 2] and trans-[RhCl(=CPh 2)(P iPr 3) 2] with ethene. The most spectacular reaction of the bis(triisopropylstibane) complexes, however, occurs on warming of trans-[RhCl(=CRR′)(Sb iPr 3) 2] in the absence of any substrate which yields the first representatives of dinuclear transition-metal compounds containing a tertiary stibane ligand in a bridging position. Some exploratory studies on the reactivity of the Rh 2(μ-Sb iPr 3) complexes indicate that the triisopropylstibane can be replaced by SbMe 3, SbEt 3 or CN tBu without destroying the dimetallic core of the molecule. 相似文献
10.
The synthesis, crystal structure and magnetic measurements of three new polynuclear tetracarboxylato-bridged copper(II) complexes, i.e. {[Cu 4(phen) 2(μ-O 2CC 2H 5) 8] · (H 2O)} n (1), [Cu 2(μ-O 2CC 6H 4OH) 4(C 7H 7NO) 2] · 6H 2O (2) and [Cu 2(μ-O 2CCH 3) 4(C 7H 7NO) 2] (3) (phen = 1,10-phenanthroline, O 2CC 6H 4OH = 3-hydroxy benzoate, C 7H 7NO = 4-acetylpyridine) are reported. All compounds consist of dinuclear units, in which two Cu(II) ions are bridged by four syn, syn-η 1:η 1:μ carboxylates, showing a paddle-wheel cage type with a square-pyramidal geometry, arranged in different ways. The structure of compound 1 consists of an one-dimensional structure generated by an alternating classical dinuclear paddle-wheel unit and an unusual dinuclear Cu 2(μ-OCOC 2H 5) 2(μ-O 2CC 2H 5) 2(phen) 2unit, which are connected to each other via a syn, anti-triatomic propionato bridge in an axial-equatorial configuration. The adjacent chains are connected to generate a 2D structure through the face-to-face π–π interaction between phen rings. Structures of compounds 2 and 3 both consist of a symmetric dinuclear Cu(II) carboxylate paddle-wheel core and pyridyl nitrogen atoms of 4-acetylpyridine ligand at the apical position, and just differ in the substituents of the equatorial ligands. The magnetic properties have been measured and correlated with the molecular structures. It is found that in the two classical paddle-wheel compounds the Cu(II) ions are strongly antiferromagnetically coupled with J = −278.5 and −287.0 cm−1 for complexes 2 and 3, respectively. In compound 1 the magnetic susceptibility could be fitted with two different, independent Cu(II) units, one strongly coupled and one weakly coupled; the paddle-wheel dinuclear unit has the strongest antiferromagetic coupling with a value for J of −299.5 cm−1, whereas the Cu(II) ions in the propionato-bridged dinuclear unit of 1 display a very weak antiferromagnetic coupling with a value for J = −0.75 cm−1, due to the orthogonality of the magnetic orbitals. Also the exchange within the chain is therefore very weak. The magneto-structural correlations for complexes 1, 2, and 3 are discussed on the basis of the structural parameters and magnetic data for the complexes. 相似文献
11.
The siloxyanilines o-Me 3SiOC 6H 4NH 2 (1) and p-RMe 2SiOC 6H 4NH 2 (R=H (2); R=Me (3)), and their N-silylated derivatives p-Me 3SiOC 6H 4NHSiMe 3 (4) and p-Me 3SiOC 6H 4N(SiMe 3) 2 (5) have been prepared from ortho- or para-aminophenol and used in the synthesis of imido complexes. Thus, binuclear [{Ti(η 5-C 5H 5)Cl}{μ-NC 6H 4( p-OSiMe 3)}] 2 (6) and mononuclear [TiCl 2{NC 6H 4( p-OSiMe 3)}(py) 3] (7) imido complexes have been obtained from the reaction of 3 and [Ti(η 5-C 5H 5)Cl 3] or [TiCl 2(N tBu)(py) 3], respectively. In contrast, the reaction of 1 with TiCl 4 and tBupy affords the titanocycle [TiCl 2{OC 6H 4( o-NH)---N,O}( tBupy) 2] (8). Compound 5 has also been used to prepare the niobium imide complex [NbCl 3{NC 6H 4( p-OSiMe 3)}(MeCN) 2] (9), by its reaction with NbCl 5 in CH 3CN. These findings have been applied to the synthesis of polynuclear systems. Thus, chlorocarbosilane Si[CH 2CH 2CH 2Si(Me) 2Cl] 4 (CS–Cl) has been functionalized with the ortho- and para-aminophenoxy groups to give 10 and 11, respectively. The use of 11 has allowed the formation of the tetranuclear compound 12. Attempts to synthesize terminal imido titanium complexes from 10 and TiCl 4 in the presence of tBupy and Et 3N, give complex 8 and carbosilane CS–Cl. 相似文献
12.
Pentacarbonyl(diethylaminocarbyne)chromium tetrafluoroborate, [(CO) 5− CrCNEt 2]BF 4 (I), reacts with PPh 3 with substitution of CO and formation of trans-tetracarbonyl(diethylaminocarbyne)triphenylphosphanechromium tetra-fluoroborate, trans-[PPh 3(CO) 4CrCNEt 2]BF 4 (III). Substitution of CO by PPh 3 in neutral trans-tetracarbonyl(halo)(diethylaminocarbyne)chromium complexes, trans-X(CO) 4CrCNEt 2 (IVa: X = Br, IVb: X = I), leads in a reversible reaction to the corresponding tricarbonyl complexes, mer-X(PPh 3)(CO) 3− CrNEt 2 (V), PPh 3 occupying the cis-position to the carbyne ligand. With PPh 3 in large excess both reactions follow a first-order rate law. This as well as the activation parameters (Δ H≠ = 104–113 kJ mol −1, Δ S≠ = 64–71 J mol −1 K −1) indicate a dissociative mechanism. 相似文献
13.
The reaction of [Nb(η 5-C 5H 4R) 2X 2] [1: R = SiMe 3, X = Cl; 2: R = SiMe 3, X = Br; 3: R = H, X = Cl; 4: R = t, X = Cl] with nitroso derivatives ArNO [ a: Ar = Ph; b: Ar = o-CH 3-C 3H 4; c: Ar = p-(CH 3) 2NC 6H 4] yields paramagnetic complexes formulated as [Nb(η 5-C 5H 4R)(η 3-C 5H 4R)X 2(ArNO- N, O) 1a, 1b, 1c, 2a, 3a, 4a and 4c, which have been characterized by ESR and IR spectroscopy. 相似文献
14.
A rapid single-step method for the electrosynthesis of chloro and bromo complexes of palladium(II and IV), viz. M 2[PdX 4] and M 2[PdX 6], by the dissolution of a palladium anode in chloride or bromide containing media is described. Electrolysis of dilute HX solution in the presence of pyridine, 2,2′-bipyridyl or 1,10-phenanthroline gives rise to non-electrolytes, e.g. trans-[PdX 2(py) 2], [PdX 2(bipy)] and [PdX 2(phen)]. Anodic oxidation of palladium in HX medium in the presence of acetonitrile and benzonitrile also gives the non-electrolytes trans-[PdX 2(CH 3CH 2NH 2) 2] and trans-[PdX 2(C 6H 5CH 2NH 2) 2], respectively. 相似文献
15.
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
16.
Complexes of the types (a) trans- and cis-[Pd(C 6X 5) 2 (CNR) 2], (b) trans- [Pd(C 6X 5)Cl(CNR) 2] and (c) [Pd(C 6X 5)(CNR) 3]ClO 4 (X = F or Cl;R = Bu t cyclohexyl or p-tolyl) have been made by replacement of the tetrahydrothiophen or Cl groups of appropriate precursors by isonitrile. Their structures have been assigned on the basis of their IR and 1H NMR spectra. 相似文献
17.
A series of novel diphosphinoazine rhodium amido carbonyl complexes [{R 2PCHC(Bu t)–NNC(Bu t)CH 2PR 2}Rh(CO)] ( R = Ph, Pr i, c-C 6H 11, Bu t) was prepared by deprotonation of cationic diphosphinoazine rhodium amino carbonyl complexes. The complexes were characterized by NMR as were also their precursors. The crystal structures of two cationic and one neutral deprotonated complex were determined by X-ray diffraction showing the complexes to be essentially planar with mutual trans arrangement of phosphine groups and nitrogens trans to carbonyl ligands. Measurement of valence vibration frequencies of carbonyl groups in the complexes allowed to estimate the electron density on the rhodium centre. The ene-hydrazone ligand backbone (nitrogen covalently bonded) is more electron donating than the azine backbone (nitrogen bonded by electron pair donation) as expected. In the neutral series of complexes electron donation increases with phosphine substitution in the order Ph < Pr i = c-C 6H 11 < Bu t with the corresponding decrease of carbonyl valence vibration frequency. The tert-butyl cationic complex undergoes in a low yield an unusual diphosphinoazine bond cleavage with simultaneous oxidation of the metal resulting in a binuclear bis(iminophosphine)dirhodium complex [{(Bu t) 2PCH 2C(Bu t)NH}Rh(Cl) 2(μ-Cl)] 2 the structure of which was also determined by X-ray diffraction. 相似文献
18.
A new series of rigid-rod alkynylferrocenyl precursors with central fluoren-9-one bridge, 2-bromo-7-(2-ferrocenylethynyl)fluoren-9-one (1b), 2-trimethylsilylethynyl-7-(2-ferrocenylethynyl)fluoren-9-one (2) and 2-ethynyl-7-(2-ferrocenylethynyl)fluoren-9-one (3), have been prepared in moderate to good yields. The ferrocenylacetylene complex 3 can provide a direct access to novel heterometallic complexes, trans-[(η 5-C 5H 5)Fe(η 5-C 5H 4)CCRCCPt(PEt 3) 2Ph] (4), trans-[(η 5-C 5H 5)Fe(η 5-C 5H 4)CCRCCPt(PBu 3) 2CCRCC(η 5-C 5H 4)Fe(η 5-C 5H 5)] (5), [(η 5-C 5H 5)Fe(η 5-C 5H 4)CCRCCAu(PPh 3)] (6) and [(η 5-C 5H 5)Fe(η 5-C 5H 4)CCRCCHgMe] (7) (R=fluoren-9-one-2,7-diyl), following the CuI-catalyzed dehydrohalogenation reactions with the appropriate metal chloride compounds. All the new complexes have been characterized by FTIR, 1H-NMR and UV–vis spectroscopies and fast atom bombardment mass spectrometry. The solid state molecular structures of 3, 5, 6 and 7 have been established by X-ray crystallography. The redox chemistry of these mixed-metal species has been investigated by cyclic voltammetry and oxidation of the ferrocenyl moiety is facilitated by the presence of the heavy metal centre and increased conjugation in the chain through the ethynyl and fluorenone linkage units. 相似文献
19.
Thermal decomposition of mixed ligand thymine (2,4-dihydroxy-5-methylpyrimidine) complexes of divalent Ni(II) with aspartate, glutamate and ADA ( N-2-acetamido)iminodiacetate dianions was monitored by TG, DTG and DTA analysis in static atmosphere of air. The decomposition course and steps of complexes [Ni(C 5H 6N 2O 2)(C 4H 5NO 4) 2−(H 2O) 2]·H 2O, [Ni(C 5H 6N 2O 2)(C 5H 7NO 4) 2−(H 2O) 2]·H 2O and [Ni(C 5H 6N 2O 2)(C 6H 8N 2O 5) 2−(H 2O) 2]·1.5H 2O were analyzed. The final decomposition products are found to be the corresponding metal oxides. The kinetic parameters namely, activation energy ( E*), enthalpy (Δ H*), entropy (Δ S*) and free energy change of decomposition (Δ G*) are calculated from the TG curves using Coats–Redfern and Horowitz–Metzger equations. The stability order found for these complexes follows the trend aspartate > ADA > glutamate. 相似文献
20.
Reaction of trans-[ReCl(CNR)(dppe) 2] (R = Me (Ia) or tBu (Ib); DPPE = Ph 2PCH 2CH 2PPh 2) in CH 2Cl 2 with cynamide in the presence of TlBF 4 forms the new cynamide-isocyanide complexes trans-[Re(CNR)(NCNH 2)(dppe) 2][BF 4] (R = Me (IIa) or tBu (IIb)), which upon treatment by tBuOK or Et 3N give trans-[Re(NCNH)(CNR)(dppe) 2] (R = Me (IIIa) or tBu (IIIb)). The electrochemical behaviour of these species was studied by cyclic voltammetry and controlled potential electrolysis at a Pt electrode in an aprotic solvent, and cathodic reduction of II results in the formation of III. 相似文献
|