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1.
《Inorganica chimica acta》1988,141(2):211-220
The reaction of CrCl3 · 6H2O (dehydrated in DMSO) with 1,5,9-triazanonane (3,3-tri) gives mer- CrCl3(3,3-tri), the configuration being established by isomorphism with the corresponding Co(III) complex. This non-electrolyte is hydrolyzed in aqueous acidic solution and mer-[CrCl2(3,3-tri)- (OH2)]ClO4 can be isolated by anation with HCl in the presence of HClO4. Reaction of mer-CrCl3- (3,3-tri) in DMF with diamines produces complexes of the type [CrCl(diamine)(3,3-tri)] Cl2 [diamine= 1,2-diaminoethane (en), 1.2-diaminopropane (pn), 1,3-diaminopropane (tn), 2,2-dimethyl-1,3-diaminopropane (Me2tn) and cyclohexanediamine (chxn, cis plus trans mixture; two isomers A and B)] and these have been characterized as the ZnCl42− salts. The configuration of the triamine ligand in these complexes has been established as mer-(H↓)- by a single crystal X-ray analysis of [CrCl(en)(3,3-tri)]- ZnCl4, monoclinic, P21, a=7.932, b= 14.711, c= 8.312 Å, β=104.6° and Z=2, refined to a conventional R factor of 0.034. The kinetics of the Hg2+- assisted chloride release from [CrCl(diamine)(3,3- tri)]ZnCl4 salts were measured spectrophotometrically (μ=1.0 M HClO4 or HNO3) over 15 K temperature ranges to give, in order, 104kHg (298.2 K) (M−1 s−1), Ea(kJ mol−1), ΔS# (J K−1 mol−1): en- (HClO4): 5.95, 78.1, -53; pn(HClO4); 5.24, 81.2; -44; tn(HClO4): 26.7, 85.6, -15; Me2tn(HClO4): 21.8, 78.6, -40; A-chxn(HNO3): 7.60, 81.0,-41; B-chxn(HNO3): 18.3, 56.8, -115. A ‘non-replaced ligand effect’ on the rate is observed for the first time in this series of homologous Cr(III) complexes. The kinetics of the thermal aquation (kH, 0.1 M HClO4) were measured titrimetrically for CrCl(diamine) (3,3-tri)2+ to give the following kinetic parameters: diamine=en: 107 kH (298.2)=5.34 s−1, Ea=99.2 kJ mol−1, ΔS#=-40 J K−1 mol-1; diamine =tn: 107 kH (298.2)=5.04 s−1, Ea= 82.8, ΔS#= -96. 相似文献
2.
Two new polynuclear complexes of Cu(II), [(μ-1,1,3-N3)2{Cu2(me2tn)2(N3)2}]n (1) (me2tn=2,2-dimethylpropane-1,3-diamine) and [Cu2(μ-C2O4)(μ-N3)(ipr2en)2]n(ClO4)n (2) (ipr2en=N,N′-di-isopropylethane-1,2-diamine) have been synthesized and structurally characterized by X-ray crystallography. The crystal structure of 1 displays a 2D network in which distorted octahedral copper(II) centers, chelated by a me2tn ligand and bound to a terminal azide, are connected through μ-1,1,3 bridging azide anions. The structure of 2 shows 1D chains comprising alternating [(ipr2en)Cu-Ox-Cu(ipr2en)] units and end-to-end azide ligand. The chains on mutual H-bonding interaction through ClO4−, give rise to a 2D supramolecular architecture. The magnetic data of complexes were recorded in the temperature range, 300-2 K. In case of complex 1, the magnetic data are consistent with a ferromagnetic interaction through the end-on azide bridge (JFM=10 cm−1) and a weak antiferromagnetic interaction (zj=−0.8 cm−1) between the ferromagnetically coupled dimers and an average g-value of 2.05. The susceptibility data of 2 were fitted using an alternating AF-AF chain spin 1/2 law which leads to the following parameters Joxalate=−180 cm−1, Jazide=−43 cm−1 and g=2.25 cm−1. 相似文献
3.
Ludger Söncksen 《Inorganica chimica acta》2011,374(1):472-479
Reaction of [Mo(O)Cl(CNMe)4]+ with the linear tetraphos ligand meso and rac prP4 leads to a mixture of [Mo(O)Cl(κ4-meso-prP4)]+ and [Mo(O)Cl(CNMe)(κ3-rac-prP4)]+ which are identified by X-ray structural analysis and/or 31P NMR spectroscopy. In the meso κ4-product both of the phenyl groups of the central phosphorus atoms are oriented towards the oxo ligand whereas in the rac κ3-product one of these phenyl groups is oriented to the oxo and the other to the chloro ligand. The origin of the different coordination modes lies in the different steric demands of the oxo and chloro ligands. The influences of the steric interactions are enhanced by the fact that exchange of the fourth isonitrile is difficult. This hypothesis is supported by the preparation of the complex [Mo(O)Cl(CNMe)(dpepp)]PF6 whose isonitrile ligand is inert towards exchange by monophosphines, even under drastic conditions. 相似文献
4.
Marco H Klingele 《Inorganica chimica acta》2004,357(5):1598-1602
The synthesis and X-ray crystal structure of the complex {[CuII(Ph2PBPT)(bpy)](ClO4)2 · 2DMF}∞ where Ph2PBPT=4,4′-(1,4-phenylene)bis[3-phenyl-5-(2-pyridyl)-4H-1,2,4-triazole], bpy=2,2′-bipyridine and DMF=N,N-dimethylformamide are reported. In this one-dimensional coordination polymer the Cu2+ ions are in a distorted octahedral N6 coordination environment made up of two Ph2PBPT molecules, each chelating via one pyridine and one triazole nitrogen, and one bpy co-ligand. Within the zig-zag chain thus formed the shortest distance between two metal centres across the Ph2PBPT ligand is 13.305(3) Å while it is 10.009(3) Å between two chains. This complex represents the first structurally characterised example of a coordination compound incorporating a chelating 4,4′-bis(4H-1,2,4-triazole) as a ligand. 相似文献
5.
《Inorganica chimica acta》1986,112(2):107-112
The synthesis and crystal and molecular structure of the first zinc(II) mixed ligand chelate containing a dithiolene ligand (maleonitriledithiolate) and N,N- diethyldithiocarbamate are reported. The compound Ph4As[Zn(mnt)(Et2dtc)] crystallizes monoclinic, space group P21/c with four molecules in the unit cell; a=17.834(3), b=12.056(2), c=16.171(4) Å, β=93.73(2)°.The coordination geometry of the ZnS4 unit is nearly tetrahedral, with a dihedral angle of 87.6° between the chelate rings. The structure is compared with those of both the patent compounds (Ph4- As)2[Zn(mnt)2] and Zn2(Et2dtc)4. Ph4As[Zn(mnt)(Et2dtc)] could be used as the host lattice in single- crystal ESR investigations of the planar Cu mixed ligand complex. The rhombic spin-Hamiltonian parameters g and ACu are indicative of a low symmetry of the incorporated [Cu(mnt)(Et2dtc)]− complex anions. In order to substantiate the experimental findings about the actual structure of the copper molecules, the principal values of g and ACu were recalculated by means of Extended Hückel MO calculations. However, the calculations performed for the dihedral angles between the ligand planes varying between 0° and 90° suggest that the rotation of the ligands is not larger than 10° 相似文献
6.
The perchlorate M(II) (M = Cu, Ni, Co) complexes with the diethyl (pyridin-4-ylmethyl)phosphate (4-pmOpe) ligand of the composition [M(4-pmOpe)2 (H2O)2](ClO4)2 (M = Ni, Co) and [Cu(4-pmOpe)2(ClO4)2] were prepared and studied. The ligand contains two donor atoms, i.e. pyridine nitrogen and phosphoryl oxygen atoms. In particular, the crystal structure of [Cu(4-pmOpe)2(ClO4)2] was determined by the X-ray method. Its structure consists of a one-dimensional polymeric chain in which copper(II) ions are N,O-bridged by two 4-pmOpe organic ligands in a trans arrangement. Two perchlorate ions occupy the fifth and the sixth coordination sites. The Cu?Cu distance is 9.180 Å. The crystal packing is determined by the weak intermolecular C-H?O hydrogen contacts. The coordination compounds were identified and characterized by elemental analysis, spectroscopic and magnetic studies. Spectroscopic and magnetic results of the copper(II) compound are presented in the light of the crystal structure. The magnetic data indicate very weak intra- and interchain magnetic exchange interactions (J’ = −0.43 and zJ’ = 0.29 cm−1, respectively). The spectroscopic and magnetic properties of the Co(II) and Ni(II) complexes indicate octahedral and polymeric structure of both compounds in which 4-pmOpe ligand also acts as N,O-bridge between metal ions. 相似文献
7.
The crystal structures of two copper(II) complexes of 4-fluorophenoxyacetic acid (4-FPAH) have been determined by X-ray diffraction. [Cu(4-FPA)2(H2O)2]·2(4-FPAH)·2H2O (1) is triclinic, space group P1 with Z = 1 in a cell of dimensions a = 14.808(2), b = 9.832(2), c = 6.847(2) Å, α = 87.77(2), β = 98.41(2), γ = 112.33(2)° and was refined to a residual of 0.038 for 1697 ‘observed’ reflections. The coordination sphere in this complex is tetragonally distorted octahedral comprising two waters [CuO, 1.940(3) Å], two unidentate carboxylate oxygens [CuO, 1.942(2) Å] and two ether oxygens [CuO, 2.471(2) Å]. Two adducted [4-FPAH] acid molecules are linked to the un-coordinated oxygens of the acid ligands by hydrogen bonds [2.547(4) Å]. [Cu2(4-FPA)4(2-aminopyrimidine)2] (2) is triclinic, space group P1 with Z = 1 in a cell of dimensions a = 12.688(2), b = 11.422(2), c = 7.951(1) Å, α = 78.74(1), β = 107.51(1), γ = 75.78(1)°, and was refined to a residual of 0.042 for 2683 ‘observed’ reflections. (2) is a centrosymmetric tetracarboxylate bridged dimer with four similar CuO (equatorial) distances [1.967–1.987 Å; 1.977(3) Å mean] and the axial position occupied by the hetero nitrogen of the 2-aminopyrimidine ligand [CuN, 2.176(3) Å]. The Cu---Cu separation is 2.710(1) Å. Crystal data are also presented which confirm the isostructurality of complex (2) with [Cu2(phenoxyacetate)4(2-aminopyrimidine)2], the CoII, MgII and MnII4-fluorophenoxyacetate complexes with their phenoxyacetic and 4-chlorophenoxyacetic acid analogues, and of CdII4-fluorophenoxyacetate with CdII and ZnII phenoxyacetates. 相似文献
8.
《Inorganica chimica acta》1986,121(1):103-111
The ligand 2-dimethylacetal-4-chloro-6-formylphenol, H(ALAC), prepared by boiling 2,6-diformyl-4-chlorophenol, H(DIAL), in methanol, was reacted with uranyl acetate to obtain the complex [UO2(ALAC)2(H2O)]. The ligand and the uranyl complex were characterized by X-ray crystallography, infrared, 1H NMR and electronic spectroscopy. Thermogravimetric and mass spectrometry data are also reported. In acid media H(ALAC) transforms easily into H(DIAL). H(ALAC) is monoclinic, P21/n, with a=13.951(5), b=7.902(5), c=9.465(5) Å, β= 91.33(3)°. The structure was refined to R=3.9%, based on 1657 observed reflexions. [UO2(ALAC)2(H2O)] is tetragonal, P43212, with a=11.147(5) and c=19.150(4) Å. The structure was refined to R=4.0%, based on 2938 observed reflexions. Four ligand oxygens and one water molecule are equatorially bonded to the uranyl group in this compound. Uranium and water oxygen lie in special positions on a crystallographic twofold axis so that the two halves of this molecule are symmetrically related. Selected bond distances for [UO2(ALAC)2(H2O)] are: UO (charged) 2.28(2) Å, UO (neutral) 2.45(2) Å, UO (uranyl) 1.77(2) Å, UO (water) 2.44(4) Å. 相似文献
9.
《Inorganica chimica acta》1988,149(2):177-185
CpRuCl(PPh3)2 reacted with excess R-DAB in refluxing toluene to give CpRuCl(R-DAB(4e)) (1a: R = i-Pr; 1b: R = t-Bu; 1c: R = neo-Pent; 1d: R =p-Tol). 1H NMR and 13C NMR spectroscopic data indicated that in these complexes the R-DAB ligand is bonded in a chelating 4e coordination mode.Reaction of 1a and 1b with one equivalent of [Co(CO)4]− afforded CpRuCo(CO)3(R-DAB(6e)) (2a: R = i-Pr; 2b: R = t-Bu). The structure of 2b was determined by a single crystal X-ray structure determination. Crystals of 2b are monoclinic, space group P21/n, with four molecules in a unit cell of dimensions: a = 16.812(4), b = 12.233(3), c = 9.938(3) Å and β = 105.47(3)°. The structure was solved via the heavy atom method and refined to R = 0.060 and Rw = 0.065 for the 3706 observed reflections. The molecule contains a RuCo bond of 2.660(3) Å and a cyclopentadienyl group that is η5-coordinated to ruthenium [RuC(cyclopentadienyl) = 2.208(3) Å (mean)]. Two carbonyls are terminally coordinated to cobalt (CoC(1) = 1.746(7) and CoC(2) = 1.715(6) Å) while the third is slightly asymmetrically bridging the RuCo bond (RuC(3) = 2.025(6) and CoC(3) = 1.912(6) Å). The RuC(3)O(3) and CoC(3)O(3) angles are 138.4(5)° and 136.5(5)°, respectively. The t-Bu-DAB ligand is in the bridging 6e coordination mode: σ-N coordinated to Ru (RuN(2) = 2.125(4) Å), μ2-N′ bridging the RuCo bond and η2-CN coordinated to Co (RuN(1) = 2.113(5), CoN(1) = 1.941(4) and CoC(4) = 2.084(5) Å). The η2-CN′ bonded imine group has a bond length of 1.394(7) Å indicating substantial π-backbonding from Co into the anti-bonding orbital of this CN bond.1H NMR spectroscopy indicated that 2a and 2b are fluxional on the NMR time scale. The fluxionality of 6e bonded R-DAB ligands is rarely observed and may be explained by the reversible interchange of the σ-N and η2-CN′ coordinated imine parts of the R-DAB ligand. 相似文献
10.
Timothy E. Patten Marilyn M. Olmstead Christina Troeltzsch 《Inorganica chimica acta》2008,361(1):365-372
The title ligand, N-(2,6-diisopropylphenyl)-2-(bis-(2-pyridylmethyl))aminoethanamide (DIPMAE-H), was prepared by a nucleophilic substitution reaction between N-(2,6-diisopropyl)phenyl-2-bromoethanamide and bis-(2-pyridylmethyl)amine. An analogous ligand (TBPMAE-H) in which the 2,6-diisopropylphenyl group was substituted for a tert-butyl group was also prepared in this manner. Then, [(DIPMAE-H)CuBr]+Br− and [(TBPMAE-H)CuBr]+Br− were prepared by heating one equivalent of ligand and CuBr2 in CH3CN. In both compounds the geometry about the copper center is square pyramidal with distortions due to the geometrical constraints of the ligand. The amide oxygen occupies the axial position, and the three amine nitrogens and the bromide ligand form the basal plane of the square pyramid. Pairs of complexes in the unit cell are associated via weak donation of a lone pair on the bromide ligand of one complex to the copper center of another (Cu?Br distances in the range of 3.3576-3.4022 Å).The title compound, (DIPMAE)CuBr, was prepared by deprotonation of [(DIPMAE-H)CuBr]+Br− using NaH. The key feature of (DIPMAE)CuBr is the amidate group η1- and N-coordinated to the copper center. The compound also exhibits distorted trigonal bipyramidal coordination geometry with the bromide and tertiary amine donors occupying the axial sites and the amidate and pyridyl donors occupying the equatorial positions. The copper atom is displaced from the trigonal plane towards the bromide donor apex due to the geometrical demands of the ligand. 相似文献
11.
The synthesis and characterisation of a series of dinuclear and polynuclear coordination compounds with 4-allyl-1,2,4-triazole are described. Dinuclear compounds were obtained for Mn(II) and Fe(II) with composition [M2(Altrz)5(NCS)4], and for Co(II) and Ni(II) with composition [M2(Altrz)4(H2O)(NCS)4](H2O)2. The crystal structure of [Co2(Altrz)4(H2O)(NCS)4](H2O)2 was solved at room temperature. It crystallizes in the monoclinic space group P21/n. The lattice constants are a = 18.033(3) Å, b = 13.611(2) Å, c = 15.619(3) Å, β = 92.04(2)° Z = 4. One cobalt ion has an octahedrally arranged donor set of ligands consisting of three vicinal nitrogens of 1,2-bridging triazoles (CoN = 2.14–2.15 Å), one terminal triazole nitrogen (CoN = 2.12 Å) and two N-bonded NCS anions (CON = 2.08 Å). The other Co(II) ion has the same geometry, but the terminal triazole ligand is replaced by H2O (CoO = 2.15 Å). The crystal structure is stabilised by hydrogen bonding through H2O molecules, S-atoms of the NCS anions and the lone-pair electron of the monodentate triazole. The magnetic exchange in the Mn, Co and Ni compounds is antiferromagnetic with J-values of ?0.4 cm?1, ?10.9 cm?1 and ?8.7 cm?1 respectively. The Co compound was interpreted in terms of an Ising model. For [Zn2(Altrz)5(NCS)2]∞[Zn(NCS)4], [Cu2(Altrz)3(NCS)4]∞ and [Cd2(Altrz)3(NCS)4]∞ chain structures are proposed. In the Cu compound thiocyanates appear to be present, bridging via the nitrogen atom, as deduced from the IR spectrum. 相似文献
12.
Vattoly J. Majo Matthew S. Milak Jaya Prabhakaran Pratap Mali Lyudmila Savenkova Norman R. Simpson J. John Mann Ramin V. Parsey J. S. Dileep Kumar 《Bioorganic & medicinal chemistry》2013,21(17):5598-5604
The 5-HT1AR partial agonist PET radiotracer, [11C]CUMI-101, has advantages over an antagonist radiotracer as it binds preferentially to the high affinity state of the receptor and thereby provides more functionally meaningful information. The major drawback of C-11 tracers is the lack of cyclotron facility in many health care centers thereby limiting widespread clinical or research use. We identified the fluoroethyl derivative, 2-(4-(4-(2-(2-fluoroethoxy)phenyl)piperazin-1-yl)butyl)-4-methyl-1,2,4-triazine-3,5(2H,4H)dione (FECUMI-101) (Ki = 0.1 nM; Emax = 77%; EC50 = 0.65 nM) as a partial agonist 5-HT1AR ligand of the parent ligand CUMI-101. FECUMI-101 is radiolabeled with F-18 by O-fluoroethylation of the corresponding desmethyl analogue (1) with [18F]fluoroethyltosylate in DMSO in the presence of 1.6 equiv of K2CO3 in 45 ± 5% yield (EOS). PET shows [18F]FECUMI-101 binds specifically to 5-HT1AR enriched brain regions of baboon. The specificity of [18F]FECUMI-101 binding to 5-HT1AR was confirmed by challenge studies with the known 5-HT1AR ligand WAY100635. These findings indicate that [18F]FECUMI-101 can be a viable agonist ligand for the in vivo quantification of high affinity 5-HT1AR with PET. 相似文献
13.
《Inorganica chimica acta》2001,312(1-2):163-169
The first tellurated derivative of morpholine, N-{2-(4-methoxyphenyltelluro)ethyl}morpholine (L1) has been synthesized by reacting in situ generated ArTe− with 4-(2-chloroethyl)morpholine hydrochloride under N2 atmosphere. The compound L1 gives molecular ion peak at m/z 351 and is characterized structurally. The donor atoms N and Te in compound L1 are rightly oriented for its ligation in bidentate mode. The TeC(alkyl) is 0.02 Å longer than TeC(aryl). The complexes of ligand L1 having composition [PtCl2(L1)2] (1) and [RuCl2(p-cymene)L1] (2) have been synthesized. The compound 1 has been characterized structurally. The Pt has a square planar geometry in complex 1 and two molecules of ligand L1 bonded through Te alone are trans to each other (PtTe=2.583(2) Å). The 13C{1H} NMR spectrum of complex 1 is as expected. The 1H NMR spectrum of single crystals of complex 1 shows multiplication of signals, which is supported by HETCOR experiments. The complex 2 also has ligand L1 in a monodentate coordination mode, bonded through Te alone. This is supported by deshielded CH2Te and ArCTe signals in 1H and 13C{1H} NMR spectra of complex 2 with respect to those of free ligand L1. The HETCOR spectrum of complex 2 has been used to authenticate the assignments of CH2Te group, as its two protons appear to be magnetically non-equivalent. 相似文献
14.
The structure of [Ph4As] [MoOCl2(SalphO)], where SalphO is N-2-oxophenylsalicylideniminate dianion, has been determined by X-ray crystallography. The complex crystallizes in the monoclinic space group P21/n with a = 11.829(2), b = 16.149(3), c = 17.410(3) Å, β = 97.485(15)° and Z = 4. The calculated and observed densities and 1.566 and 1.573(10) g cm?3, respectively. Block-diagonal least-squares refinement of the structure using 4722 independent reflections with I ? 3σ(I) converged at R = 0.0345 and Rw = 0.0484. The crystal contains [Ph4As]+ cations and [MoOCl2(SalphO)]? anions. The Mo atom in the anion is in a distorted octahedral coordination environment. A planar terdentate Schiff base ligand occupies meridional positions with the N atom trans to the terminal oxo group (Ot). Two Cl atoms are cis to the Ot atom. The Mo atom is displaced by 0.33 Å from the equatorial plane toward the Ot atom. The MoOt distance is 1.673(3) Å. The MoN bond trans to the Ot atom is 2.298(4) Å. The two MoCl bond lengths are 2.371(1) and 2.408(1) Å. The difference of 0.037 Å is significant (30 σ). Preparations of the title complex and the related complexes are also described. 相似文献
15.
Ligand exchange reactions of oxorhenium(V) precursors with bidentate SN and tridentate Schiff bases derived from the condensation of ketones or aldehydes with dithiocarbazic acid methyl ester (H2NNHC(S)SCH3) produce novel ‘3+2’ mixed-ligand complexes carrying the SNO/SN donor atom set. Thus, reactions of either [NBu4][ReOCl4] or Na[ReO(Gluconate)2] with SNO ligands (H2Ln) or a mixture of bidentate SN (HLm) and tridentate SNO (H2Ln) in methanol solutions lead, respectively, to the six-coordinated mixed ligand oxorhenium(V) compounds of types [ReO(Ln)(HLn)] and [ReO(Ln)(Lm)], combining one tridentate dianionic S−NO− donor Schiff base (L) and one bidentate anionic S−N donor ligand (HL). Coordination geometry around rhenium is distorted octahedral with the two SN donor atom sets of each ligand defining the equatorial plane, while apical positions are occupied by the oxo group and the oxygen atom of the tridentate SNO ligand (L), as shown by single-crystal X-ray diffraction structure of [ReO(L1)(HL1)] 1. 相似文献
16.
We present here the syntheses of a mononuclear CuII complex and two polynuclear CuII NiII complexes of the azenyl ligand, 4‐(pyridin‐2‐ylazenyl)resorcinol (HL; 1). The reaction of HL ( 1 ) and copper(II) perchlorate with KCN gave a mononuclear complex [CuL(CN)] ( 4 ). Using 4 , one pentanuclear complex, [{CuL(NC)}4Ni](ClO4)2 ( 5 ) and one trinuclear complex, [{CuL(CN)}2NiL]ClO4 ( 6 ), were prepared and characterized by elemental analyses, magnetic susceptibility, molar conductance, IR, and thermal analysis. Stoichiometric and spectral results of the mononuclear CuII complex indicated that the metal/ligand/CN ratio was 1 : 1 : 1, and the ligand behaved as a tridentate ligand forming neutral metal chelates through the pyridinyl and azenyl N‐, and resorcinol O‐atom. The interaction between the compounds (the ligand 1 , its NiII and CuII complexes without CN, i.e., 2 and 3 , and its complexes with CN, 4 – 6 ) and DNA has also been investigated by agarose gel electrophoresis. The pentanuclear Cu4Ni complex ( 5 ) with H2O2 as a co‐oxidant exhibited the strongest DNA‐cleaving activity. 相似文献
17.
《Inorganica chimica acta》1988,154(1):95-97
Aerial recrystallization of the mononuclear molybdenum(V) complex {HB(Me2pz)3}MoO(OC6H4-o-S) produced the novel binuclear Mo(VI) complex [{HB(Me2pz)3}MoO2(OC6H4- o-S)]2 which contains a disulfide bond. The dimer crystallizes as the dioxane solvate in the space group C2/c with cell parameters a=23.46(2), b=11.100(4), c=21.571(8) Å, β=104.23(4)°, Z=4. Final Rw=0.062 (2236 reflections with Fo>3σ(Fo), 301 variable parameters). The dimer contains two crystallographically identical distorted octahedral MoO22+ centers. One face of each octahedron is occupied by two oxo ligands and a phenolate oxygen atom; the opposite face is occupied by three nitrogens of the HB(Me2pz)3− ligand. The two Mo(VI) centers of the dimers are linked by a disulfide bond formed upon oxidation of the 2-mercaptophenolate ligand of the original molybdenum(V) compound. 相似文献
18.
Jessica Gätjens 《Inorganica chimica acta》2009,362(3):878-886
Bernhard Lippert has contributed significantly to the understanding of metallamacrocyclic complexes with low valent, late transition metals. In particular, he has pioneered the preparation of metallacalixarenes such as 12-MC-3 and 16-MC-4 structure types. In this article, we provide the preparation of a new 16-MC-4, [Mn4Br4(B(tBuM)PZG)4] [Mn(HOCO2)2], complex made with the ligand potassium N,N-bis(3-methyl-5-tert-butylpyrazolylmethyl)glycinate (KB(tBuM)PZG). In addition to being the first 16-MC-4 that is composed of manganese, this complex is the first example of a transition metal [Mn(II)] being captured in the interior cavity of the 16-MC-4. We discuss how our ligand design leads to the isolated structure due to the steric bulk that has been appended to the pyrazole ligand. 相似文献
19.
《Inorganica chimica acta》1988,146(1):75-84
The kinetics of rapid CO substitution by PPh3 in Co4(CO)12 and Rh4(CO)12 have been examined by stopped-flow and low temperature FT-IR methods. In Co4(CO)12 rapid (kobs ∼ 1.8 s−1) substitution of CO occurs after a 1–15 s induction period at 28 °C in C6H5Cl solvent by a catalytic process. Addition of PPh3 to Rh4(CO)12 yields Rh4(CO)11(PPh3) according to a predominantly second order rate law k1[Rh4- (CO)12] + k2[Rh4(CO)12][PPh3] with k1 = 25 ± 11 s−1 and k2 = 2.97 ± 0.27 X 104 M−1 s−1 at 28 °C. Substitution of a second CO ligand also occurs rapidly with k1 = 0.15 ± 0.09 s−1 and k2 = 6.54 ± 0.07 X 102 M−1 s−1 at 28 °C. The reactivity of Rh4(CO)12 toward associative substitution is 104– 1011 faster than for the Co and Ir analogues, In Rh4(CO)11(PPh3) the increase in CO substitution rates over Co and Rh analogues is 102–107. The ordering of associative substitution rates Co << Rh >>> Ir in these clusters exaggerates the trend seen in mononuclear metal complexes. 相似文献
20.
The binding modes of the [Ru(II)(1,10-phenanthroline)(L1L2) dipyrido[3,2-a:2′,3′-c]phenazine]2+ {[Ru(phen)(py) Cl dppz]+ (L1 = Cl, L2 = pyridine) and ([Ru(phen)(py)2dppz]2+ (L1 = L2 = pyridine)} to native DNA is compared to that of the [Ru(II)(1,10-phenanthroline)2dipyrido[3,2-a:2′,3′-c]phenazine]2+ complex ([Ru(phen)2dppz]2+) by various spectroscopic and hydrodynamic methods including electric absorption, linear dichroism (LD), fluorescence spectroscopy, and viscometric titration. All measured properties, including red-shift and hypochromism in the dppz absorption band, nearly perpendicular molecular plane of the dppz ligand with respect to the local DNA helix axis, prohibition of the ethidium binding, the light switch effect and binding stoichiometry, increase in the viscosity upon binding to DNA, increase in the melting temperature are in agreement with classical intercalation of dppz ligand of the [Ru(phen)2dppz]2+ complex, in which both phenanthroline ligand anchored to the DNA phosphate groups by electrostatic interaction. [Ru(phen)(py)2 dppz]2+ and [Ru(phen)(py) Cl dppz]+ complexes had one of the phenanthroline ligand replaced by either two pyridine ligands or one pyridine plus a chlorine ion. They exhibited similar protection from water molecules, interaction with DNA bases, and occupying site that is common with ethidium. The dppz ligand of these two Ru(II) complex were greatly tilted relative to the DNA helix axis, suggesting that the dppz ligand resides inside the DNA and is not perpendicular relative to the DNA helix axis. These observation suggest that anchoring the [Ru(phen)2dppz]2+complex by both phenanthroline is essential for the dppz ligand to be classically intercalated between DNA base-pairs. 相似文献