共查询到20条相似文献,搜索用时 156 毫秒
1.
The Substitution Reactions of the Small Biomolecules and Dinuclear Pt(II) Complexes with Alkanediamine Linker
下载免费PDF全文
![点击此处可从《国际化学动力学杂志》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The substitution reactions of the complexes [{trans‐Pt(NH3)2H2O}2(μ‐1,4‐diaminobutane)]4+ ( I ), [{trans‐Pt(NH3)2H2O}2(μ‐1,6‐diaminohexane)]4+ ( II ), and [{trans‐Pt(NH3)2H2O}2(μ‐1,8‐diaminooctane)]4+ ( III ), with nucleophiles L‐cysteine (L‐Cys), glutathione (GSH), guanosine‐5′‐monophosphate (5′‐GMP), L‐histidine (L‐His), and pyridine were studied in 0.1 M NaClO4 aqueous solutions at pH = 2.5. The substitutions were studied under pseudo‐first‐order conditions as a function of concentration and temperature using UV–vis spectrophotometry. At three different temperatures (288, 298, and 308 K) the reactions of the II and III complexes and 5′‐GMP were studied. The order of reactivity of study ligands is L‐Cys > GSH > 5′‐GMP > L‐His > pyridine and the order of reactivity of the complexes is I < II ≈ III . The obtained results indicate that the structure of the alkanediamine linker in the dinuclear Pt(II) complexes controls the substitution process. The negative values reported for entropy of activation confirmed the associative substitution mode. These results are discussed in order to find the connection between structure and reactivity of the dinuclear Pt(II) complexes. 相似文献
2.
Braunschweig H Bertermann R Brenner P Burzler M Dewhurst RD Radacki K Seeler F 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(42):11828-11837
A stable trans‐(alkyl)(boryl) platinum complex trans‐[Pt(BCat′)Me(PCy3)2] (Cat′=Cat‐4‐tBu; Cy=cyclohexyl=C6H11) was synthesised by salt metathesis reaction of trans‐[Pt(BCat′)Br(PCy3)2] with LiMe and was fully characterised. Investigation of the reactivity of the title compound showed complete reductive elimination of Cat′BMe at 80 °C within four weeks. This process may be accelerated by the addition of a variety of alkynes, thereby leading to the formation of the corresponding η2‐alkyne platinum complexes, of which [Pt(η2‐MeCCMe)(PCy3)2] was characterised by X‐ray crystallography. Conversion of the trans‐configured title compound to a cis derivative remained unsuccessful due to an instantaneous reductive elimination process during the reaction with chelating phosphines. Treatment of trans‐[Pt(BCat′)Me(PCy3)2] with Cat2B2 led to the formation of CatBMe and Cat′BMe. In the course of further investigations into this reaction, indications for two indistinguishable reaction mechanisms were found: 1) associative formation of a six‐coordinate platinum centre prior to reductive elimination and 2) σ‐bond metathesis of B? B and C? Pt bonds. Mechanism 1 provides a straightforward explanation for the formation of both methylboranes. Scrambling of diboranes(4) Cat2B2 and Cat′2B2 in the presence of [Pt(PCy3)2], fully reductive elimination of CatBMe or Cat′BMe from trans‐[Pt(BCat′)Me(PCy3)2] in the presence of sub‐stoichiometric amounts of Cat2B2, and evidence for the reversibility of the oxidative addition of Cat2B2 to [Pt(PCy3)2] all support mechanism 2, which consists of sequential equilibria reactions. Furthermore, the solid‐state molecular structure of cis‐[Pt(BCat)2(PCy3)2] and cis‐[Pt(BCat′)2(PCy3)2] were investigated. The remarkably short B? B separations in both bis(boryl) complexes suggest that the two boryl ligands in each case are more loosely bound to the PtII centre than in related bis(boryl) species. 相似文献
3.
Dr. Jaroslav Malina Prof. Dr. Nicholas P. Farrell Prof. Dr. Viktor Brabec 《化学:亚洲杂志》2011,6(6):1566-1574
The trinuclear platinum compound [{trans‐PtCl(NH3)2}2(μ‐trans‐Pt(NH3)2{NH2(CH2)6NH2}2)]4+ (BBR3464) belongs to the polynuclear class of platinum‐based anticancer agents. These agents form in DNA long‐range (Pt,Pt) interstrand cross‐links, whose role in the antitumor effects of BBR3464 predominates. Our results show for the first time that the interstrand cross‐links formed by BBR3464 between two guanine bases in opposite strands separated by two base pairs (1,4‐interstrand cross‐links) exist as two distinct conformers, which are not interconvertible, not only if these cross‐links are formed in the 5′‐5′, but also in the less‐usual 3′‐3’ direction. Analysis of the conformers by differential scanning calorimetry, chemical probes of DNA conformation, and minor groove binder Hoechst 33258 demonstrate that each of the four conformers affects DNA in a distinctly different way and adopts a different conformation. The results also support the thesis that the molecule of antitumor BBR3464 when forming DNA interstrand cross‐links may adopt different global structures, including different configurations of the linker chain of BBR3464 in the minor groove of DNA. Our findings suggest that the multiple DNA interstrand cross‐links available to BBR3464 may all contribute substantially to its cytotoxicity. 相似文献
4.
Mozhgan Samandar Sangari Mehdi Rashidi S. Masoud Nabavizadeh Banafshe Askari Fatemeh Niroomand Hosseini 《应用有机金属化学》2018,32(1)
Oxidative addition of 2‐phenylethylbromide (PhCH2CH2Br) to dimethylplatinum(II) complexes [PtMe2(NN)] ( 1a , NN = 2,2′‐bipyridine (bpy); 1b , NN = 1,10‐phenanthroline (phen)) afforded the new organoplatinum(IV) complexes [PtMe2(Br)(PhCH2CH2)(bpy)], as a mixture of trans ( 2a ) and cis ( 3a ) isomers, and [PtMe2(Br)(PhCH2CH2)(phen)], as a mixture of trans ( 2b ) and cis ( 3b ) isomers, respectively. The new Pt(IV) complexes were readily characterized using multinuclear (1H and 13C) NMR spectroscopy and elemental microanalysis. The crystal structure of 2a was further determined using X‐ray crystallography indicating an octahedral geometry around the platinum centre. A comparison of reactivity of RCH2Br reagents (R = CH3, Ph or PhCH2) in their oxidative addition reactions with complex 1a , with an emphasis on the effects of the R groups of alkyl halides, was also conducted using density functional theory. 相似文献
5.
《Journal of Coordination Chemistry》2012,65(6):659-665
A series of novel trans-mixed diamine platinum(II) and platinum(IV) complexes of type trans-[PtII(R-NH2)(R'-NH2)Cl2] and trans -[PtIV(R-NH2)(R'-NH2)Cl4] (where R-NH2 = ethylamine or butylamine and R'-NH2 = methylamine, propylamine, isopropylamine, pentylamine, or hexylamine) was synthesized and characterized using elemental analysis and infrared and 195Pt nuclear magnetic resonance spectroscopic techniques. 相似文献
6.
The reactions of platinum(II) complexes, [PtCl2(dach)] (dach = (1R,2R)‐1,2‐diaminocyclohexane) and [PtCl2(en)] (en = ethylenediamine) with biologically relevant ligands such as 5′‐GMP (guanosine‐5′‐monophosphate) and l ‐His (l ‐histidine) were studied by UV–vis spectrophotometry, 1H NMR spectroscopy, and high‐performance liquid chromatography (HPLC). Spectrophotometrically, these reactions were investigated under pseudo‐first‐order conditions at 310 K in 25 mM Hepes buffer (pH 7.2) and 10 mM NaCl to prevent the hydrolysis of the complexes. The [PtCl2(en)] complex reacts faster than [PtCl2(dach)] in the reaction with studied nucleophiles. This confirms the fact that the reactivity of studied Pt(II) complexes depends on the structure of the inert bidentate ligand. Also, the substitution reactions with l ‐His are always faster than the reactions with nucleotide 5′‐GMP. The reactions of [PtCl2(dach)] and [PtCl2(en)] complexes with l ‐histidine are studied by 1H NMR spectroscopy. The obtained rate constants are in agreement with those obtained by UV–vis. The same reactions were studied by HPLC comparing the obtained chromatograms during the reaction. The changes in intensity of signals of the free and coordinated ligand show that after a few days there is only one dominant product in the system. © 2010 Wiley Periodicals, Inc. Int J Chem Kinet 43: 99–106, 2011 相似文献
7.
Leticia Cubo Dr. Angela Casini Dr. Chiara Gabbiani Dr. Guido Mastrobuoni Dr. Luigi Messori Prof. Jesús Jiménez‐Barbero Prof. Carmen Navarro‐Ranninger Prof. Adoración G. Quiroga Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(36):9139-9146
A novel trans‐platinum(II) complex bearing one dimethylamine (dma) and one methylamine (ma) ligand, namely trans‐[PtCl2(dma)(ma)], recently synthesised and characterised in our laboratory, displayed relevant antiproliferative properties in vitro, being more active than the parent complex, trans‐[PtCl2(dma)(ipa)], which has isopropylamine (ipa) in place of methylamine. We have analysed comparatively the solution behaviour of these two complexes under various experimental conditions, and investigated their reactivity with horse heart cytochrome c by mass spectrometry, inductively coupled plasma–optical emission spectroscopy (ICP‐OES), 2D [1H,15N],[1H,13C] HSQC and [1H,1H] NOESY NMR. Some important changes that occurred in the [1H,13C] HSQC NMR spectrum of cytochrome c treated with trans‐[PtCl2(dma)(ma)] in water, after two days’ incubation, most probably arose from direct platinum coordination to the protein side chain; this was proved conclusively by [1H,1H] NOESY NMR and [1H,15N] HSQC NMR measurements. Met65 was identified as the primary Pt binding site on cytochrome c. Electrospray mass spectrometry (ESIMS) results provided evidence for extensive platinum–protein adduct formation. A fragment of the [Pt(amine)(amine′)] type was established to be primarily responsible for protein metalation. ICP‐OES analysis revealed that these trans‐platinum(II) complexes bind preferentially to the serum proteins albumin and transferrin rather than to calf thymus DNA. Pt binding to DNA was found to be far lower than in the case of cisplatin. The implications of the results for the mechanism of action of novel cytotoxic trans‐platinum complexes are discussed. 相似文献
8.
Jiří Schulz Anna K. Renfrew Ivana Císařová Paul J. Dyson Petr Štěpnička 《应用有机金属化学》2010,24(5):392-397
The polar phosphanyl‐carboxamide, 1′‐(diphenylphosphanyl)‐1‐[N‐(2‐hydroxyethyl)carbamoyl]ferrocene ( 1 ), reacts readily with hydrogen peroxide and elemental sulfur to give the corresponding phosphane‐oxide and phosphane‐sulfide, respectively, and with platinum(II) and palladium(II) precursors to afford various bis(phosphane) complexes [MCl2( 1 ‐κP)2] (M = trans‐Pd, trans‐Pt and cis‐Pt). The anticancer activity of the compounds was evaluated in vitro with the complexes showing moderate cytotoxicities towards human ovarian cancer cells. Moreover, the biological activity was found to be strongly influenced by the stereochemistry, with trans‐[PtCl2( 1 ‐κP)2] being an order of magnitude more active than the corresponding cis isomer. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
9.
Stefanus Otto Andreas Roodt 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(5):540-541
The crystal structure of the title compound, trans‐[PtI2(C6H12N3P)2], describes one of the few platinum(II) complexes containing two of the water‐soluble 1,3,5‐triaza‐7‐phosphaadamantane ligands reported to date. The complex crystallizes on an inversion centre with the most important bond lengths and angles being Pt—P 2.3128 (12) Å, Pt—I 2.6022 (6) Å, P—Pt—I 90.94 (3)° and P′—Pt—I 89.06 (3)°. 相似文献
10.
Synthesis, Crystal Structures, and Vibrational Spectra of trans ‐[Pt(N3)4(ECN)2]2–, E = S, Se By oxidative addition to (n‐Bu4N)2[Pt(N3)4] with dirhodane in dichloromethane trans‐(n‐Bu4N)2[Pt(N3)4(SCN)2] and by ligand exchange of trans(n‐Bu4N)2[Pt(N3)4I2] with Pb(SeCN)2 trans‐(n‐Bu4N)2[Pt(N3)4(SeCN)2] are formed. X‐ray structure determinations on single crystals of trans‐(Ph4P)2[Pt(N3)4(SCN)2] (triclinic, space group P 1, a = 10.309(3), b = 11.228(2), c = 11.967(2) Å, α = 87.267(13), β = 75.809(16), γ = 65.312(17)°, Z = 1) and trans‐(Ph4P)2[Pt(N3)4(SeCN)2] (triclinic, space group P 1, a = 9.1620(10), b = 10.8520(10), c = 12.455(2) Å, α = 90.817(10), β = 102.172(10), γ = 92.994(9)°, Z = 1) reveal, that the compounds crystallize isotypically with octahedral centrosymmetric complex anions. The bond lengths are Pt–S = 2.337, Pt–Se = 2.490 and Pt–N = 2.083 (S), 2.053 Å (Se). The approximate linear Azidoligands with Nα–Nβ–Nγ‐angles = 172,1–175,0° are bonded with Pt–Nα–Nβ‐angles = 116,7–120,5°. In the vibrational spectra the platinum chalcogen stretching vibrations of trans‐(n‐Bu4N)2[Pt(N3)4(ECN)2] are observed at 296 (E = S) and in the range of 186–203 cm–1 (Se). The platinum azide stretching modes of the complex salts are in the range of 402–425 cm–1. Based on the molecular parameters of the X‐ray determinations the IR and Raman spectra are assigned by normal coordinate analysis. The valence force constants are fd(PtS) = 1.64, fd(PtSe) = 1.36, fd(PtNα) = 2.33 (S), 2.40 (Se) and fd(NαNβ, NβNγ) = 12.43 (S), 12.40 mdyn/Å (Se). 相似文献
11.
Michael I. Bruce Julianne Davy Ben C. Hall Yvonne Jansen van Galen Brian W. Skelton Allan H. White 《应用有机金属化学》2002,16(10):559-568
Several trans‐platinum(II) complexes, of the type R′? {Pt(PBu3)2}? R″? {Pt(PR3)2}? R′, where R′ and R″ are groups derived from a series of aromatic alkynes and diynes, have been prepared and characterized. Extensive spectroscopic data for these and other known related complexes are presented. A more precise structural study of trans‐Pt(C≡CC6H4C≡CPh)2(PBu3)2 (cf. Z. Kristallogr. 1998; 213: 483) is reported. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
12.
The cis‐Diammineplatinum(II) Complex of Curcumin: A Dual Action DNA Crosslinking and Photochemotherapeutic Agent
下载免费PDF全文
![点击此处可从《Angewandte Chemie (International ed. in English)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Koushambi Mitra Srishti Gautam Prof. Paturu Kondaiah Prof. Akhil R. Chakravarty 《Angewandte Chemie (International ed. in English)》2015,54(47):13989-13993
[Pt(cur)(NH3)2](NO3) ( 1 ), a curcumin‐bound cis‐diammineplatinum(II) complex, nicknamed Platicur, as a novel photoactivated chemotherapeutic agent releases photoactive curcumin and an active platinum(II) species upon irradiation with visible light. The hydrolytic instability of free curcumin reduces upon binding to platinum(II). Interactions of 1 with 5′‐GMP and ct‐DNA indicated formation of platinum‐bound DNA adducts upon exposure to visible light (λ=400–700 nm). It showed apoptotic photocytotoxicity in cancer cells (IC50≈15 μM ), thus forming ?OH, while remaining passive in the darkness (IC50>200 μM ). A comet assay and platinum estimation suggest Pt–DNA crosslink formation. The fluorescence microscopic images showed cytosolic localization of curcumin, thus implying possibility of dual action as a chemo‐ and phototherapeutic agent. 相似文献
13.
《Journal of Coordination Chemistry》2012,65(7):815-819
Cisplatin analogues, cis-dichloro(ethylenediamine-N,N′-di-3-propanoic acid)platinum(II) (1) and cis-iodo(ethylenediamine-N,N′-di-3-propanoic acid)platinum(II) (2), as well as trans-dichloro-(ethylenediamine-N,N′-di-3-propanoato)platinum(IV) (3), trans-dibromo(ethylenediamine -N,N′-di-3-propanoato)platinum(IV) (4), trans-dichloro(propylenediamine-N,N′-diacetato)-platinum(IV) (5) and trans-dibromo(propylenediamine-N,N′-diacetato)platinum(IV) (6), -([Pt(H2eddp)Cl2], [Pt(Heddp)I], trans-[Pt(eddp)Cl2], trans-[Pt(eddp)Br2], trans-[Pt(pdda)Cl2] and trans-[Pt(pdda)Br2], respectively) were used to assess antitumor selectivity against human adenocarcinoma HeLa cells. The results show that different oxidation states of platinum, different halide ligands, chelating aminocarboxylato and diamine backbones have similar effects with edda-type ligands and activity is lower than for cisplatin. 相似文献
14.
Yoshiki Ozawa Misa Kim Koshiro Toriumi 《Acta Crystallographica. Section C, Structural Chemistry》2013,69(2):146-149
A new one‐dimensional platinum mixed‐valence complex with nonhalogen bridging ligands, namely catena‐poly[[[bis(ethane‐1,2‐diamine‐κ2N,N′)platinum(II)]‐μ‐thiocyanato‐κ2S:S‐[bis(ethane‐1,2‐diamine‐κ2N,N′)platinum(IV)]‐μ‐thiocyanato‐κ2S:S] tetrakis(perchlorate)], {[Pt2(SCN)2(C2H8N2)4](ClO4)4}n, has been isolated. The PtII and PtIV atoms are located on centres of inversion and are stacked alternately, linked by the S atoms of the thiocyanate ligands, forming an infinite one‐dimensional chain. The PtIV—S and PtII...S distances are 2.3933 (10) and 3.4705 (10) Å, respectively, and the PtIV—S...PtII angle is 171.97 (4)°. The introduction of nonhalogen atoms as bridging ligands in this complex extends the chemical modifications possible for controlling the amplitude of the charge‐density wave (CDW) state in one‐dimensional mixed‐valence complexes. The structure of a discrete PtIV thiocyanate compound, bis(ethane‐1,2‐diamine‐κ2N,N′)bis(thiocyanato‐κS)platinum(IV) bis(perchlorate) 1.5‐hydrate, [Pt(SCN)2(C4H8N2)2](ClO4)2·1.5H2O, has monoclinic (C2) symmetry. Two S‐bound thiocyanate ligands are located in trans positions, with an S—Pt—S angle of 177.56 (3)°. 相似文献
15.
Rasha A. Ruhayel Joseph J. Moniodis Dr. Xiaohong Yang Dr. Jana Kasparkova Dr. Viktor Brabec Prof. Susan J. Berners‐Price Prof. Nicholas P. Farrell Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(37):9365-9374
Reported herein is a study of the unusual 3′–3′ 1,4‐GG interstrand cross‐link (IXL) formation in duplex DNA by a series of polynuclear platinum anticancer complexes. To examine the effect of possible preassociation through charge and hydrogen‐bonding effects the closely related compounds [{trans‐PtCl(NH3)2}2(μ‐trans‐Pt(NH3)2{NH2(CH2)6NH2}2)]4+ (BBR3464, 1 ), [{trans‐PtCl(NH3)2}2(μ‐NH2(CH2)6NH2)]2+ (BBR3005, 2 ), [{trans‐PtCl(NH3)2}2(μ‐H2N(CH2)3NH2(CH2)4)]3+ (BBR3571, 3 ) and [{trans‐PtCl(NH3)2}2{μ‐H2N(CH2)3‐N(COCF3)(CH2)4}]2+ (BBR3571‐COCF3, 4 ) were studied. Two different molecular biology approaches were used to investigate the effect of DNA template upon IXL formation in synthetic 20‐base‐pair duplexes. In the “hybridisation directed” method the monofunctionally adducted top strands were hybridised with their complementary 5′‐end labelled strands; after 24 h the efficiency of interstrand cross‐linking in the 5′–5′ direction was slightly higher than in the 3′–3′ direction. The second method involved “postsynthetic modification” of the intact duplex; significantly less cross‐linking was observed, but again a slight preference for the 5′–5′ duplex was present. 2D [1H, 15N] HSQC NMR spectroscopy studies of the reaction of [15N]‐ 1 with the sequence 5′‐d{TATACATGTATA}2 allowed direct comparison of the stepwise formation of the 3′–3′ IXL with the previously studied 5′–5′ IXL on the analogous sequence 5′‐d(ATATGTACATAT)2. Whereas the preassociation and aquation steps were similar, differences were evident at the monofunctional binding step. The reaction did not yield a single distinct 3′–3′ 1,4‐GG IXL, but numerous cross‐linked adducts formed. Similar results were found for the reaction with the dinuclear [15N]‐ 2 . Molecular dynamics simulations for the 3′–3′ IXLs formed by both 1 and 2 showed a highly distorted structure with evident fraying of the end base pairs and considerable widening of the minor groove. 相似文献
16.
Summary The platinum(II) carboxylates,trans-Pt(O2CR)2(py)2 and Pt(O2CR)2bpy (R=C6F5,p-HC6F4,m-HC6F4, oro-HC6F4; bpy=2,2-bipyridyl), have been prepared by reactions oftrans-Pt(OH)2(py)2 or Pt(OH)2bpy with the appropriate polyfluorobenzoic acids, whilst [Pt(py)4](O2CC6F5)2 has been obtained from reaction oftrans-PtCl2(py)2 with thallous pentafluorobenzoate in pyridine at room temperature. In boiling pyridine, the platinum(II) polyfluorobenzoates undergo either decarboxylation givingtrans-PtR2(py)2 and PtR2bpy (R= C6F5,p-HC6F4, orm-HC6F4) complexes or substitution, giving [Pt(py)4](O2CC6F4H-o)2 and [Ptbpy(py)2](O2CC6F4H-o)2. Reactions oftrans-PtX2(py)2 and PtX2bpy (X=Cl or Br) with appropriate thallous polyfluorobenzoates in boiling pyridine have yielded the complexestrans-PtR2(py)2, PtR2bpy, PtCl(R)bpy (R=C6F5,p-HC6F4, orm-HC6F4 in each case),trans-PtCl(R)(py)2 (R = C6F5 orm-HC6F4),trans-PtBr(C6F5)(py)2, and PtBr(C6F5)bpy. The complexestrans-PtR2(py)2 (R=C6F5 orp-HC6F4) have also been prepared from potassium tetrachloroplatinate(II) and the appropriate thallous polyfluorobenzoate in boiling py, andtrans-Pt(C6F5)2(py)2 has been similarly obtained fromcis-PtCl2(py)2 and C6F5CO2Tl. Significant decarboxylation was not observed on reaction oftrans-PtCl2(py)2 or PtCl2bpy with thallous 2,3,4,5-tetrafluorobenzoate.Part II, ref. 4;Preliminary communication, ref. 3; 相似文献
17.
Maria H. Johansson ke Oskarsson Karin Lvqvist Fotini Kiriakidou Pramesh Kapoor 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(9):1053-1055
Both cis‐ and trans‐dichlorobis(diphenyl sulfide)platinum(II), [PtCl2(C12H10S)2], crystallize as mononuclear pseudo‐square‐planar complexes. In the cis compound, the Pt—Cl distances are 2.295 (2) and 2.319 (2) Å, and the Pt—S distances are 2.280 (2) and 2.283 (2) Å. In the trans compound, Pt is located on a centre of inversion and the Pt—Cl and Pt—S distances are 2.2786 (15) and 2.3002 (12) Å, respectively. 相似文献
18.
《国际化学动力学杂志》2018,50(3):215-221
New complexes of arylplatinum(II) and arylplatinum(IV) containing a bridging ligand, 4,4′‐bipyridine, were synthesized by the reaction of starting material of platinum(II) including para‐tolyl groups,[(p‐MeC6H4)2Pt(SMe2)2], with the 4,4′‐bipyridine ligand in 1:1 molar stoichiometry. In the synthesized complexes, the ligand was bonded to the platinum center through the nitrogen donor atoms. To investigate the kinetic reaction of the platinum(II) complex with iodomethane (CH3‐I) as a reagent, the oxidative addition reaction of this reagent with Pt(II) was performed in dichloromethane and a Pt(IV) complex with the octahedral geometry was formed. The synthesized complexes have been characterized by different spectroscopic methods such as FT‐IR, 1H NMR, UV–vis, and elemental analysis. Moreover, the conductivity measurements showed nonelectrolyte characteristics for these complexes. The obtained data showed that the complexes have 1:1 metal‐to‐ligand molar ratio. Also, the oxidative addition reaction of CH3I with the arylplatinum(II) complex at different temperatures was used for obtaining kinetic parameters such as rate constants, activation energy, entropy, and enthalpy of activation using the Microsoft Excel solver. From the acquired data, an SN2 mechanism was suggested for the oxidative addition reaction. 相似文献
19.
In this screening study in vitro, two polymer‐conjugated, square‐planar platinum(II) complexes bound to the carrier via a single primary amine ligand were tested for antineoplastic activity against the HeLa human cervical epithelioid carcinoma cell line. In the first of these conjugates, 1‐Pt , the spacer connecting the metal complex with the carrier backbone is a short oligo(ethylene oxide) segment, whereas a long poly(ethylene oxide) chain represents the spacer unit in the second conjugate, 2‐Pt . IC50 data, expressed as conjugate concentration at 50% cell growth inhibition, are 48 µg Pt ml−1 for 1‐Pt and 120 µg Pt ml−1 (estimated) for 2‐Pt , the long tether in the latter conjugate presumably causing retarded enzymic release and lysosomal membrane crossing of the monomeric complex. The IC50 value of 1‐Pt is close to that (44 µg Pt ml−1) of a similar conjugate of an earlier investigation, 3‐Pt , in which the metal is chelated by two carrier‐attached, cis‐oriented amino groups in conformance with the ligand arrangement in cisplatin. It thus appears that, in the carrier‐bound state, both monoamine‐ and cis‐diamine‐coordinated platinum(II) complexes of suitable structures may well show similar biological performance patterns. Copyright© 1999 John Wiley & Sons, Ltd. 相似文献
20.
Synthesis, Crystal Structures, and Vibrational Spectra of trans ‐[Pt(N3)4X2]2–, X = Cl, Br, I By oxidative addition to (n‐Bu4N)2[Pt(N3)4] with the elemental halogens in dichloromethane trans‐(n‐Bu4N)2[Pt(N3)4X2], X = Cl, Br, I are formed. X‐ray structure determinations on single crystals of trans‐(Ph4P)2[Pt(N3)4Cl2] (triclinic, space group P1, a = 10.352(1), b = 10.438(2), c = 11.890(2) Å, α = 91.808(12), β = 100.676(12), γ = 113.980(10)°, Z = 1), trans‐(Ph4P)2[Pt(N3)4Br2] (triclinic, space group P1, a = 10.336(1), b = 10.536(1), c = 12.119(2) Å, α = 91.762(12), β = 101.135(12), γ = 112.867(10)°, Z = 1) and trans‐(Ph4P)2[Pt(N3)4I2] (triclinic, space group P1, a = 10.186(2), b = 10.506(2), c = 12.219(2) Å, α = 91.847(16), β = 101.385(14), γ = 111.965(18)°, Z = 1) reveal, that the compounds crystallize isotypically with octahedral centrosymmetric complex anions. The bond lengths are Pt–Cl = 2.324, Pt–Br = 2.472, Pt–I = 2.619 and Pt–N = 2.052–2.122 Å. The approximate linear Azidoligands with Nα–Nβ–Nγ‐angles = 172.1–176.8° are bonded with Pt–Nα–Nβ‐angles = 116.2–121.9°. In the vibrational spectra the platinum halogen stretching vibrations of trans‐(n‐Bu4N)2[Pt(N3)4X2] are observed in the range of 327–337 (X = Cl), at 202 (Br) and in the range of 145–165 cm–1 (I), respectively. The platinum azide stretching modes of the three complex salts are in the range of 401–421 cm–1. Based on the molecular parameters of the X‐ray determinations the IR and Raman spectra are assigned by normal coordinate analysis. The valence force constants are fd(PtCl) = 1.90, fd(PtBr) = 1.64, fd(PtI) = 1.22, fd(PtNα) = 2.20–2.27 and fd(NαNβ, NβNγ) = 12.44 mdyn/Å. 相似文献