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1.
Reactions of 2-(arylazo)aniline, HL [H represents the dissociable protons upon orthometallation and HL is p-RC6H4N = NC6H4-NH2; R = H for HL1; CH3 for HL2 and Cl for HL3] with Ru(R1-tpy)Cl3 (where R1-tpy is 4′-(R1)-2,2′,6′′,2′′-terpyridine and R1 = H or 4-N,N-dimethylaminophenyl or 4-methylphenyl) afford a group of complexes of type [Ru(L)(R1-tpy)]·ClO4 each of which contains C,N,N coordinated L as a tridentate ligand along with a terpyridine. Structure of one such complex has been determined by X-ray crystallography. All the Ru(II) complexes are diamagnetic, display characteristic 1H NMR signals and intense dπ(RuII) → π∗(tpy) MLCT transitions in the visible region. Cyclic voltammetric studies on [Ru(L)(R1-tpy)]·ClO4 complexes show Ru(II)-Ru(III) oxidation within 0.63-0.67 V versus SCE.  相似文献   

2.
X-ray structures are presented of three new cobalt complexes prepared from Co(III) and N,N-1,10-phenanthroline-5,6-dione. The cis-aqua-chloro-bis(N,N-1,10-phenanthroline-5,6-dione)cobalt(II) nitrate trihydrate (3) and the cis-aqua-bromo-bis(N,N-1,10-phenanthroline-5,6-dione)cobalt(II) trifluoro-methanesulfonate tetrahydrate (4), crystalize in the same space group with a similar arrangement of the complex ions. However, on the molecular scale there are important differences. The cobalt complex in 3 has a typical high-spin geometry whereas in 4 the cobalt complex displays a Jahn-Teller distortion characteristic for low-spin compounds. The third structure is di(N,N-1,10-phenanthroline-5,6-diol)(N,N-1,10-phenanthroline-5,6-dione)cobalt(III) bromide hexahydrate (5). NMR studies of the hydration of the Co(III)(1,10-phenanthroline-5,6-dione)3 3+ ion in water and DMSO are also presented. The various possible transformations of the N,N-1,10-phenanthroline-5,6-dione ligand are discussed.  相似文献   

3.
This report describes synthesis and evaluation of cationic complexes, [99mTc(CO)3(L)]+ (L = N-methoxyethyl-N,N-bis[2-(bis(3-ethoxypropyl)phosphino)ethyl]amine (L1), N-[(15-crown-5)-2-yl]-N,N-bis[2-(bis(3-ethoxypropyl)phosphino)ethyl]amine (L2) and N-[(18-crown-6)-2-yl]-N,N-bis[2-(bis(3-ethoxypropyl)phosphino)ethyl]amine (L3)) as potential radiotracers for heart imaging. Preliminary results from biodistribution studies in female adult BALB-c mice indicated that the cationic 99mTc(I)-tricarbonyl complex, [99mTc(CO)3(L2)]+, has a significant localization in the heart at 60 min post-injection. To understand the coordination chemistry of these bisphosphine ligands with the 99mTc(I)-tricarbonyl core, we prepared [Re(CO)3(L4)]Br (L4: N,N-bis[(2-diphenylphosphino)ethyl]methoxyethylamine) as a model compound. [Re(CO)3(L4)]Br has been characterized by elemental analysis, IR, ESI-MS, NMR (1H, 13C, 1H-1H COSY, and 1H-13C HMQC) methods, and X-ray crystallography. In solid state, [Re(CO)3(L4)]+ has a distorted octahedron coordination geometry with PNP occupying one facial plane. The chelator backbone adopts a “chair” conformation with phosphine-P atoms at equatorial positions and the amine-N at the apical site. In solution, [Re(CO)3(L4)]+ is able to maintain its cationic nature with no dissociation of carbonyl ligands or any of the three PNP donors.  相似文献   

4.
Previous work has shown that Y-family DNA polymerases tolerate large DNA adducts, but a substantial decrease in catalytic efficiency and fidelity occurs during bypass of N2,N2-dimethyl (Me2)-substituted guanine (N2,N2-Me2G), in contrast to a single methyl substitution. Therefore, it is unclear why the addition of two methyl groups is so disruptive. The presence of N2,N2-Me2G lowered the catalytic efficiency of the model enzyme Sulfolobus solfataricus Dpo4 16,000-fold. Dpo4 inserted dNTPs almost at random during bypass of N2,N2-Me2G, and much of the enzyme was kinetically trapped by an inactive ternary complex when N2,N2-Me2G was present, as judged by a reduced burst amplitude (5% of total enzyme) and kinetic modeling. One crystal structure of Dpo4 with a primer having a 3′-terminal dideoxycytosine (Cdd) opposite template N2,N2-Me2G in a post-insertion position showed Cdd folded back into the minor groove, as a catalytically incompetent complex. A second crystal had two unique orientations for the primer terminal Cdd as follows: (i) flipped into the minor groove and (ii) a long pairing with N2,N2-Me2G in which one hydrogen bond exists between the O-2 atom of Cdd and the N-1 atom of N2,N2-Me2G, with a second water-mediated hydrogen bond between the N-3 atom of Cdd and the O-6 atom of N2,N2-Me2G. A crystal structure of Dpo4 with dTTP opposite template N2,N2-Me2G revealed a wobble orientation. Collectively, these results explain, in a detailed manner, the basis for the reduced efficiency and fidelity of Dpo4-catalyzed bypass of N2,N2-Me2G compared with mono-substituted N2-alkyl G adducts.  相似文献   

5.
A tetranuclear copper(II) complex [Cu4L2(CH3COO)2(OH)2]·6H2O, in which L stands for the dianion of N-(3-carboxylsalicylidene)-4-(2-iminoethyl)morpholine, was synthesized and characterized by elemental analysis, IR, UV-Vis, TGA and X-ray single crystal diffraction. The crystal structure shows that the coordination unit is centrosymmetric with all the Cu(II) ions in square pyramidal coordination geometry. The coordination unit consists of two equivalent parts [Cu2L(CH3COO)(OH)], each containing two Cu(II) ions, a tetradentate N2O2 Schiff base dianion L2−, a CH3COO, and a OH anion. In [Cu2L(CH3COO)(OH)], the six coordination atoms (N2O4) are nearly coplanar, with Cu(1) and Cu(2) enchased in between; the phenolate oxygen and the OH oxygen as bridging atoms bind the two Cu(II) ions in close proximity; both O4 around Cu(1) and N2O2 around Cu(2) form the basal plane of the coordination square pyramids. The two parts are connected by sharing two μ3-OH oxygens and two μ2-CH3COO oxygens from each other, forming four edge-sharing coordination square pyramids around the four Cu(II) ions. A 3D network is formed through hydrogen bonding along a and c axis, and π-π interaction along b axis.  相似文献   

6.
The reaction of 2-(diphenylphosphino)-N-[2-(diphenylphosphino)benzylidene]benzeneamine (PNCHP) with 0.5 equivalents of [{RhCl(1,5-cyclooctadiene)}2] affords the extremely, air-sensitive compound, [RhCl(PNCHP-κ3P,N,P)]. This reacts with carbon monoxide to afford [RhCl(CO)(PNCHP-κ3P,N,P)] which rearranges in dichloromethane solution to [Rh(CO)(PNCHP-κ3P,N,P)]Cl · HCl. The single crystal structure of [Rh(CO)(PNCHP-κ3P,N,P)]Cl · HCl shows the Rh to be in a square planar environment with the HCl molecule held via hydrogen bonding in the lattice. NMR experiments show the coordinated chloride in [RhCl(PNCHP-κ3P,N,P)] can be substituted with tetrahydrofuran, acetonitrile or triphenylphosphine and the complex undergoes oxidative addition with dichloromethane to yield [Rh(CH2Cl)Cl2(PNCHP-κ3P,N,P)].  相似文献   

7.
Nickel(II) complexes of N,N′-dimethyl-N,N′-bis(pyridyl-2yl-methyl)ethylene-diamine (L1), N,N′-dimethyl-N,N′-bis(pyridyl-2-ylmethyl)-1,2-diaminopropane (L2) and N,N′-dimethyl-N,N′-bis(pyridyl-2-ylmethyl)-1,3-diaminopropane (L3) were prepared and their spectroscopic and redox properties studied. The distorted octahedral structure was determined for [NiL3ClCH3OH](ClO4) by using X-ray crystallography. The electronic spectral behavior of the complexes at different pHs was analyzed; it is shown that a new band grew at the expense of the other band intensity in acid media. The redox properties of ligands and their complexes show the peaks of Ni(II) → Ni(III) and Ni(II) → Ni(0) as these were detected at low concentration while Ni(II) → Ni(I) process was detectable clearly at high concentration. Furthermore, the interaction studies of 2-mercaptoethanesulfonic acid as a simulator of coenzyme M reductase (CoM) with NiN4 chromophores are discussed.  相似文献   

8.
A series of new cobalt(III) complexes were prepared. They are [CoL1(py)3]·NO3 (1), [CoL2(bipy)(N3)]·CH3OH (2), [CoL3(HL3)(N3)]·NO3 (3), and [CoL4(MeOH)(N3)] (4), where L1, L2, L3 and L4 are the deprotonated form of N′-(2-hydroxy-5-methoxybenzylidene)-3-methylbenzohydrazide, N′-(2-hydroxybenzylidene)-3-hydroxylbenzohydrazide, 2-[(2-dimethylaminoethylimino)methyl]-4-methylphenol, and N,N′-bis(5-methylsalicylidene)-o-phenylenediamine, respectively, py is pyridine, and bipy is 2,2′-bipyridine. The complexes were characterized by infrared and UV–Vis spectra, and single crystal X-ray diffraction. The Co atoms in the complexes are in octahedral coordination. Complexes 1 and 4 show effective urease inhibitory activities, with IC50 values of 4.27 and 0.35 μmol L−1, respectively. Complex 2 has medium activity against urease, with IC50 value of 68.7 μmol L−1. While complex 3 has no activity against urease. Molecular docking study of the complexes with Helicobacter pylori urease was performed.  相似文献   

9.
A series of copper(II) complexes, i.e. Cu2LCl4, CuLCl2·H2O and [Cu2L2Cl4]·2MeCN (8), based on a new potentially polytopic ligand, 3,5-bis(4,6-dimethylpyrimidin-2-yl)-4H-1,2,4-triazol-4-amine (3b, L), have been synthesized. The crystal structures of L and [Cu2L2Cl4]·2MeCN were studied by X-ray single crystal analysis. The dinuclear compound [Cu2L2Cl4]·2MeCN represents the first example of structurally characterized metal complexes with 3,5-di(pyrimidin-2-yl)-4H-1,2,4-triazol-4-amines. Both copper atoms have distorted tetragonal-pyramidal 3N + 2Cl environment. Surprisingly, in contrast to the complexes based on 3,5-di(pyridin-2-yl)-4H-1,2,4-triazol-4-amine (pyridinyl analog of L), the compound [Cu2L2Cl4]·2MeCN adopts a dinuclear trans-(N′,N1,N2)2 double bridging binding mode which is due to tridentate coordination of two L molecules linking two copper atoms through N1,N2-triazole and N′-pyrimidine atoms. It seems to be reasonable that it is methyl groups in pyrimidinyl moiety that obstruct the expected dinuclear (N′,N1,N2,N″)2 double bridging coordination being one of the most common for 4-substituted 3,5-di(pyridin-2-yl)-4H-1,2,4-triazoles and 3,5-di(pyridin-2-yl)-1,2,4-triazolates. Due to π-π stacking interactions, molecules of Cu2L2Cl4 in the structure of [Cu2L2Cl4]·2MeCN form 1D chains.  相似文献   

10.
Manganese(II) complexes [Mn(L)X2] were prepared and characterized, where L is a neutral di-Schiff base ligand incorporating pyridylimine donor arms, including (1R,2R)-N,N′-bis(2-pyridylmethylidene)-1,2-diphenylethylenediimine (L1), (1R,2R)-N,N′-bis(6-methyl-2-pyridylmethylidene)-1,2-cyclohexyldiimine (L2), or (1R,2R)-, (1S,2S)- or racemic N,N′-bis(2-pyridylmethylidene)-1,2-cyclohexyldiimine (L3), and X =  or Cl. Product complexes were structurally characterized, specifically including [Mn(R,R-L1)(NCCH3)3](ClO4)2, [Mn(R,R-L2)(OH2)2](ClO4)2 and racemic [Mn(L3)Cl2]. The first of these complexes features a heptacoordinate ligand field in a distorted pentagonal bipyramid, and the latter two are hexacoordinate, but retain equatorially monovacant pentagonal bipyramidal structures. Complexes [Mn(L3)X2] (X = Cl, ) were reacted with the primary phosphine FcCH2PH2 (Fc = -C5H4FeC5H5), H2O and ethyldiazoacetate (EDA). The first two substrates prompted reactivity at a single ligand imine bond, resulting in hydrophosphination and hydrolysis, respectively. Complexes of the derivative ligands were also structurally characterized. Evidence for EDA activation was obtained by electrospray ionization mass spectrometry, but catalytic carbene transfer was not obtained.  相似文献   

11.
The complexes [Re{MeN(CH2CH2O)(CH2CH2OH)-κ3N,O,O}(CO)3] (1), [Re{N(CH2CH2O)(CH2CH2OH)23N,O,O}(CO)3] (2), [Me3NH]2[(OC)3Re{N(CH2CO2)23N,O,O}CH2CH2{N(CH2CO2)23N,O,O}Re(CO)3] (3), [Me3NH]2[Re22-2,6-(O2C)2(C5H3N)-κ3N,O,O}2(CO)6] (4) and [Re22-2,6-(OCH2)(C5H3N)(CH2OH)-κ2N,O}2(CO)6] (5) were synthesized in high yields via the reactions of [Re2(CO)10] and Me3NO with MeN(CH2CH2OH)2, N(CH2CH2OH)3, EDTA, pyridine-2,6-dicarboxylic acid and pyridine-2,6-dimethanol, respectively. Complexes 1-5 were characterized by IR and 1H NMR spectroscopy, elemental analysis and X-ray crystallography.  相似文献   

12.
The potentially tritopic bridging ligand 4-(pyrid-4-yl)-1,2,4-triazole (pytz) reacts with cadmium(II) nitrate tetrahydrate, Cd(NO3)2·4H2O and sodium dicyanamide (Na-dca) to form the molecular complex [Cd(dca)2Npy-pytz)2(H2O)2] (1). The cadmium atom lies on a center of inversion and is coordinated in a slightly distorted octahedral geometry by the trans-oriented pytz ligands, dicyanamide anions and aqua ligands. The pytz ligand coordinates through the Npyridin atom to the metal atom. The molecular complexes are connected to a 3D supramolecular network by O-H···Ndca and O-H···Ntriazole hydrogen bonds. From zinc(II) bromide and pytz the compound 1D-[ZnBr2(μ-κNpy,Ntz-pytz)] (2) is obtained where the pytz-ligand bridges between the tetracoordinated zinc(II) atoms through coordination of its Npyridine- and Ntriazole-atoms. Adjacent chains are connected through C-H···Br and C-H···N hydrogen bonds to form a 3D supramolecular structure. Single crystals of 2 crystallize homochiral in the non-centrosymmetric space group P212121. The origin of the homochirality is the formation of hydrogen-bonded helices around the 21 screw axes with the same sense of rotation (left-handed or M in the investigated crystal). Cd(NO3)2·4H2O, pytz and sodium thiocyanate (NaSCN) give the framework 3D-[Cd(μ-SCN)2(μ-κNpy,Ntz-pytz)] (3). Parallel layers of 2D-{Cd(μ-SCN)2}-nets with distorted (6,3)-net topology are assembled by the bridging pytz-ligands into a 3D-structure. The pytz-ligand bridges between two cadmium atoms by Npyridine- and Ntriazole-coordination.  相似文献   

13.
The light green coloured complexes of general formula [ReVO(L)Cl(OH2)]Cl have been synthesised in good yields by reacting [ReVOCl3(AsPh3)2] with HL in dichloromethane in dinitrogen atmosphere. Here, L is the deprotonated form of N,N-bis(2-pyridylmethyl)amine (HL1); N-(2-pyridylmethyl)-N′,N′-dimethylethylenediamine (HL2) and N-(2-pyridylmethyl)-N′,N′-diethylethylenediamine (HL3). Single crystal X-ray structure determination of [ReVO(L1)Cl(OH2)]Cl confirms the amido binding of ReO3+ species. In the solid state of [ReVO(L1)Cl(OH2)]Cl, the coordinated and counter chloride ions are engaged in Re-Cl…H-C(ring), Cl…H-C(ring) and Re-(OH2)…Cl hydrogen bonding and forming of a supramolecular network in the solid state. The subunit of the supramolecular network consists of one eight-membered and two nine-membered hydrogen bonded rings. The average diameters of eight-membered and nine-membered rings are ∼3.70 and ∼5.26 Å, respectively.  相似文献   

14.
Reported are four iron(II) complexes with N-benzyl-N,N′-bis(2-pyridylmethyl)-1,2-ethanediamine (LH) and three electronically modified derivatives: N-(4-methoxy)benzyl-N,N′-bis(2-pyridylmethyl)-1,2-ethanediamine (LOMe), N-(4-chloro)benzyl-N,N′-bis(2-pyridylmethyl)-1,2-ethanediamine (LCl), and N-(4-nitro)benzyl-N,N′-bis(2-pyridylmethyl)-1,2-ethanediamine (LNO2). The four ligands react with FeCl2 to form a series of mononuclear species with the general formula [Fe(LR)Cl2]. The cis-α conformation of the ligand places the amine N-donors trans to the Fe-Cl bonds. The identity of the 4-benzyl substituent has profound influences on the lengths of the iron-ligand bonds, the optical spectra, and the redox activities of the [Fe(LR)Cl2] compounds.  相似文献   

15.
《Inorganica chimica acta》1986,121(2):223-228
One isomer of [CrCl(N-Me-tn)(dien)]ZnCl4 has been isolated from the reaction of CrCl3·6H2O, dehydrated in DMF, with the polyamines N-methyl- 1,3-diaminopropane and diethylenetriamine. This complex is isomorphous with δλ-(R,S)usft-[CoCl(N-Me-tn)(dien)] ZnCl4 and thus has the unsym-fac- configuration with the N-Me group trans to the sec-NH group of the coordinated triamine. The Cr(III) complex has been resolved with NH4BCS and the chiroptical parameters of (-)488-[CrCl(N-Me-tn)(dien)]- ZnCl4, derived from the less soluble diastereoisomeride by metathesis, are similar to those obtained for the less soluble (-)534-λ-(S)-a,cb,edf-Co(III) analogue, of known absolute configuration. Kinetic parameters for the rates of thermal aquation (μ= 1.0 M, HClO4) and Hg2+-assisted chloride release (μ= 1.0 M) for usft-[CrCl(N-Me-tn)(dien)]ZnCl4 are kH= 3.7 × 10−6 s−1, Ea=93 ± 8 kJ mol−1, ΔS2984t#= −45 ± 16 J K−1 mol−1 and kHg=2.01 × 10−3 M−1 s−1, Ea=64.2 ± 3.3, ΔS298#=−89.5 ± 7, respectively at 298 K.  相似文献   

16.
The new adduct 3-(2-carboxyethyl)cytosine (3-CEC) was isolated following in vitro reaction of the carcinogen β-propiolactone (BPL) with calf thymus DNA. The structure of 3-CEC was confirmed by synthesis from BPL and dCyd. Reaction of BPL with cCyd (pH 7.0–7.5, 37°C) gave 3-(2-carboxyethyl)deoxycytidine (3-CEdCyd) (9% yield) and 3,N4-bis(2-carboxyethyl)deoxycytidine (3,N4-BCEdCyd) (0.6% yield). 3-CEdCyd and 3,N4-BCEdCyd were hydrolyzed (1.5 N HC1, 100°C, 2 h) to 3-CEC and 3,N4-bis(2-carboxyethyl)cytosine (3,N4-BCEC), respectively. The structure of 3-CEC was assigned on the basis of UV and NMR spectra and the electron impact (EI) mass spectra of 3-CEC and a tri-trimethylsilyl (TMS) derivative of 3 CEC as well as deuterated (d27) tri-TMS derivative of 3-CEC. The structure of 3,N4-BCEC was assigned on the basis of UV spectra and the EI mass spectra of a tri-TMS derivative. EI and isobutane chemical ionization mass spectra of 3-methylcytosine (3-MeCyt) and a di-TMS derivative of 3-MeCyt were obtained and were helpful in deducing the structures of 3-CEC and 3,N4-BCEC. This is the first report of the alkylation by BPL of an exocyclic atom on a base in DNA. Compound 3,N4-BCEC was not detected in BPL-reacted calf thymus DNA. The relative amounts of 1-(2-carboxyethyl)adenine (1-CEA), 7-(2-carboxyethyl)guanine (7-CEG), 3-(2-carboxyethyl)thymine (3-CET) and 3-CEC isolated from BPL-reacted DNA following perchloric acid hydrolysis were 0.23, 1.00, 0.39 and 0.41 respectively, when the alkylation reaction was conducted in phosphate buffer at 0–5°C and pH 7.5 and 0.10, 1.00, 0.29 and 0.28 respectively when the reaction was conducted in H2O at 37°C and pH 7.0–7.5.  相似文献   

17.
Ag+-assisted dechlorination of blue cis-trans-cis Ru(R-aai-R)2Cl2 followed by the reaction with chloranilic acid (H2CA) in presence of Et3N gives a neutral mononuclear violet complex [Ru(R-aai-R)2(CA)]. [R-aai-R=p-R-C6H4-NN-C3H2-NN-1-R, abbreviated as N,N chelator, where N(imidazole) and N(azo) represent N and N, respectively; R=H (a), Me (b), Cl (c) and R=Me (4), Et (5), CH2Ph (6)]. The structure in one case, [Ru(Cl-aai-Et)2(CA)] has been established by X-ray diffraction study. The π-π stacking and H-bonding network give a supramolecular ladder. All the complexes exhibit strong intense MLCT transition in the visible region and weak broad bands in higher wavelength (>700 nm). Visible transition (580-595 nm) shows negative solvatochromic effect. The cyclic voltammograms show two quasi-reversible to irreversible couples at positive to SCE and are due to CA/CA2− (1.2-1.4 V) and Ru(III)/Ru(II) (1.6-1.8 V) redox processes. Three couples negative to SCE are assigned to CA2−/CA3− (−0.2 to −0.3 V) and azo reductions (−0.5 to −0.7, −0.8 to −0.9 V) of the chelated R-aai-R. The molecular orbital calculation (ZINDO/1, ZINDO/S) supports the spectral feature and electrochemical properties of the complexes.  相似文献   

18.
Two new neutral, binuclear CuIICuII bis(oxamato) complexes with the formula [Cu2(opba)(pmdta)(MeOH)] · 1/2MeOH · dmf (3) and [Cu2(nabo)(pmdta)(MeOH)] (4), with opba = o-phenylene-bis(oxamato), nabo = 2,3-naphthalene-bis(oxamato), pmdta = N,N,N′,N″,N″-pentamethyldiethylenetriamine and dmf = dimethylformamide have been synthesized and their crystal structures have been determined. The structure of 3 consists of dimeric [Cu2(opba)(pmdta)(MeOH)] entities, joined together by mutual intermolecular Cu?O contacts of the Cu2+ ion of one [Cu(opba)]2− complex fragment and one carboxylate atom of the oxamato group of a second [Cu(opba)]2− complex fragment. The structure of 4 consists of neutral binuclear complexes joined together by hydrogen bonds and π-π interactions, giving rise to an unique supramolecular 1D-chain. The magnetic properties of 3 and 4 were studied by susceptibility measurements versus temperature. For the intramolecular J parameter, identical values of (−114 ± 2) cm−1 (3) and (−112 ± 2) cm−1 (4) were obtained.  相似文献   

19.
We have developed four 99mTc(CO)3-labeled lipophilic tracers as potential radiolabeling agents for cells based on a hexadecyl tail. 99mTc(CO)3-hexadecylamino-N,N′-diacetic acid (negatively charged), 99mTc(CO)3-hexadecylamino-N-α-picolyl-N′-acetic acid (uncharged), 99mTc(CO)3-N,N′-dipicolylhexadecylamine (positively charged), 99mTc(CO)3-N-hexadecylaminoethyl-N′-aminoethylamine (positively charged) were prepared in a radiolabeling yield: >90%. Preliminary cell uptake studies were performed in mixed blood cells with or without plasma and were compared with 99mTc-d,l-HMPAO and [18F]FDG. In plasma-free blood cells, maximum uptake (78%) was obtained for 99mTc(CO)3-N-hexadecylaminoethyl-N′-aminoethylamine after 60 min incubation (compared to 55% and 23% for 99mTc-d,l-HMPAO and [18F]FDG, respectively) while in plasma-rich medium, 99mTc(CO)3-N,N′-dipicolylhexadecylamine was best bound (54%, similar to the binding of 99mTc-d,l-HMPAO). Biodistribution in normal mice showed mainly hepatobiliary clearance of the agents and initial high lung uptake. The radiolabeled compounds showed good blood clearance with maximally 7.9% injected dose per gram at 60 min post injection. While the least lipophilic agent (99mTc(CO)3-N,N′-dipicolylhexadecylamine, log P = 1.3) showed the best cell uptake, there appears to be no direct correlation between lipophilicity and tracer uptake in mixed blood cells. In view of its comparable cell uptake to well known cell labeling agent 99mTc-d,l-HMPAO, 99mTc(CO)3-N,N′-dipicolylhexadecylamine merits further evaluation as a potential cell labeling agent.  相似文献   

20.
Several platinum(II) complexes of the general type [Pt(OND)X] have been prepared and characterized, the ligand (OND) representing the phenolate anion of the tridentate Schiff bases N-(2- diethylaminoethyl)-salicylaldimine (D = NEt2), N-(2- ethylaminoethyl)-salicylaldimine (D = NHEt) and N- (3-thia-n-pentyl)-salicylaldimine (D= SEt) and X= Cl, NO3. As shown by conductimetric studies the nitrato complexes [Pt(OND)NO3] dissociate completely in methanol according to:
Spectrophotometry (normal and stopped-flow) has been used to study the kinetics of solvent substitution according to
with a variety of neutral and anionic nucleophiles Y in methanol at 20 °C and constant ionic strength, I= 0.2 M (NaClO4). The substitution follows a one- term rate law, v = kobs[Pt(OND)(H2O)+] = kY[Y]- [Pt(OND)(H2O)+]. The kY data obtained for 13 (D = NEt2) and 7 (D = NHEt; SEt) different nucleophiles Y cannot be adequately correlated with their npt0 values according to the well-known relationship log kY = snpt0 + log ks. The deviations are strongest for large and bulky nucleophiles such as Y=Ph3P, Bu3P, Ph3As, I- and for D = NEt2, from which it is concluded that steric crowding hinders the formation of the 5-coordinate transition state. The rate reducing steric cis-effect observed is of the order kY(D = NEt2):kY(D = NHEt):kY(D = SEt) = 1:35:63 for small nucleophiles Y and as large as 1:192:2640 for Y = Ph3P. The introduction of substituents X in the salicylaldehyde ring in ortho (X3), meta (X4) and para position (X5) to the phenolic oxygen proves the existence of rather small electronic effects (X4, X5) and much stronger steric effects of bulky substituents X3, neighboring the donor oxygen.With the standard substrate trans-[Ptpy2Cl2] some new npt0 values were determined, namely for N, N′- dimethylthiourea (npt0 = 7.02), N, N′ -diphenylthlourea (npt0 = 7.19), N, N, N′, N′-tetramethylthiourea (npt0 = 6.05) and for the pseudo-halide dicyanoamide ion, N(CN)2- (npt0= 3.05). The npt0 value for the pseudo-halide tricyanomethanide, ion, C(CN)3-, was estimated to be 3.03.  相似文献   

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