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1.
The ligand 1,4,7-triazacyclononane-1,4,7-tris[2′(R)-2′-propionate](-3)((R)-tacntp3−), binds stereospecifically to transition metal ions. The structures of the complexes [Cr((R)-tacntp)]·NaBr and [Fe((R)-tacntp)]·H2O have been determined by X-ray crystallography. Both complexes have the Λ-configuration but the conformation of the chelate rings in Λ-[Cr((R)-tacntp)] is (λ,λ,λ) with a geometry close to octahedral while in Λ-[Fe((R)-tacntp)] it is (δ,δ,δ) and the geometry is closer to that of a trigonal prism. Chiral induction in the electron transfer reactions of Λ-[Co((R)-tacntp)], Λ-[Fe((R)-tacntp)] and Λ-[Mn((R)-tacntp)] with [Co((RR,SS)-chxn)3]2+ has been investigated. All three reactions are outer-sphere and four isomeric [Co((RR,SS)-chxn)3]3+ products are identified in each case. The oxidants Λ-[Fe((R)-tacntp)] and Λ-[Mn((R)-tacntp)] show very similar selectivities, quite different from those of Λ-[Co((R)-tacntp)]. Reasons for this behavior are discussed. 相似文献
2.
Methods for determining the differential susceptibility of human organs to DNA damage have not yet been explored to any large extent due to technical constraints. The development of comprehensive analytical approaches by which to detect intertissue variations in DNA damage susceptibility may advance our understanding of the roles of DNA adducts in cancer etiology and as exposure biomarkers at least. A strategy designed for the detection and comparison of multiple DNA adducts from different tissue samples was applied to assess esophageal and peripherally- and centrally-located lung tissue DNA obtained from the same person. This adductome approach utilized LC/ESI-MS/MS analysis methods designed to detect the neutral loss of 2′-deoxyribose from positively ionized 2′-deoxynucleoside adducts transmitting the [M+H]+ > [M+H−116]+ transition over 374 transitions. In the final analyses, adductome maps were produced which facilitated the visualization of putative DNA adducts and their relative levels of occurrence and allowed for comprehensive comparisons between samples, including a calf thymus DNA negative control. The largest putative adducts were distributed similarly across the samples, however, differences in the relative amounts of putative adducts in lung and esophagus tissue were also revealed. The largest-occurring lung tissue DNA putative adducts were 90% similar (n = 50), while putative adducts in esophagus tissue DNA were shown to be 80 and 84% similar to central and peripheral lung tissue DNA respectively. Seven DNA adducts, N2-ethyl-2′-deoxyguanosine (N2-ethyl-dG), 1,N6-etheno-2′-deoxyadenosine (dA), -S- and -R-methyl-γ-hydroxy-1,N2-propano-2′-deoxyguanosine (1,N2-PdG1, 1,N2-PdG2), 3-(2′-deoxyribosyl)-5,6,7,8-tetrahydro-8-hydroxy-pyrimido[1,2-a]purine-(3H)-one (8-OH-PdG) and the two stereoisomers of 3-(2′-deoxyribosyl)-5,6,7,8-tetrahydro-6-hydroxypyrimido[1,2-a]purine-(3H)-one (6-OH-PdG) were unambiguously detected in all tissue DNA samples by comparison to authentic adduct standards and stable isotope dilution and their identities were matched to putative adducts detected in the adductome maps. 相似文献
3.
Lefoix M Coudert G Routier S Pfeiffer B Caignard DH Hickman J Pierré A Golsteyn RM Léonce S Bossard C Mérour JY 《Bioorganic & medicinal chemistry》2008,16(9):5303-5321
We describe here an efficient synthesis of new 5-azaindolocarbazoles designed for cytotoxic and Chk1 inhibiting properties. The synthesis of ‘symmetrical’ and ‘dissymmetrical’ structures is discussed. Concerning the dissymmetrical 5-azaindolocarbazoles derivatives, with both an indole moiety and a 5-azaindole moiety, the synthesis was achieved using two very efficient key steps. The first one is a Stille reaction with a 3-trimethylstannyl-5-azaindole derivative and the second one a photochemical step leading to the proposed polycyclic structure. Various pharmacomodulations were performed to investigate the structure–activity relationships (SAR). Several substituents such as OBn, OH, and methylenedioxy groups were successfully introduced on the indole moiety of the 5-azaindolocarbazole. Compounds with or without substituents on the nitrogen atom of the maleimide were prepared, as well as derivatives with glucopyranosyl substituent on the nitrogen atom of the indole moiety. The cytotoxicity of these new compounds was evaluated on two cell lines (L1210, HT29). Several compounds showed cytotoxicity in the sub-micromolar range. Among the most cytototoxic was the 1,3-dioxolo[4,5-b]-6-(2-dimethylaminoethyl)-1H-pyrido[3′,4′:4,5]pyrrolo[3,2-i]pyrrolo[3,4-g]carbazole-5,7(6H,12H)-dione (35, IC50 = 195 nM on L1210). The compounds were also investigated for their Chk1 inhibiting activity. Compounds without any substitution on the maleimide moiety were the most potent. This is the case of compounds 45–47 with IC50 of, respectively, 72, 27, and 14 nM toward Chk1. Compound 46, which exhibits moderate cytotoxicity, appears to be a good candidate for development in a multi-drug anticancer therapy. 相似文献
4.
Yu D Kandimalla ER Roskey A Zhao Q Chen L Chen J Agrawal S 《Bioorganic & medicinal chemistry》2000,8(1):275-284
Stereo-enriched [Rp] and [Sp]-phosphorothioate oligodeoxynucleotides are synthesized using oxazaphospholidine derivatized monomers. Three different designs of phosphorothioate oligodeoxynucleotides (PS-oligos), (i) stereo-enriched all-[Rp] or all-[Sp] PS-linkages, (ii) stereo-random mixture of PS-linkages, and (iii) segments containing certain number of stereo-enriched [Rp] and [Sp] PS-linkages ([Sp-Rp-Sp] or [Rp-Sp-Rp]), have been studied. Thermal melting studies of these PS-oligos with RNA complementary strands showed that the binding affinities are in the order [Rp] > [Sp-Rp-Sp]-[Rp-Sp-Rp] > stereo-random > [Sp]. Circular dichroism (CD) studies suggest that the stereochemistry of the PS-oligo does not affect the global conformation of the duplex. The in vitro nuclease stability of these PS-oligos is in the order [Sp] > [Sp-Rp-Sp] > stereo-random > [Rp]. The RNase H activation is in the order [Rp] > stereo-random > [Rp-Sp-Rp] > [Sp] > [Sp-Rp-Sp]. Studies in a cancer cell line of PS-oligos targeted to MDM2 mRNA showed that all oligos had similar biological activity under the experimental conditions employed. Protein- and enzyme-binding studies showed insignificant stereo-dependent binding to proteins. The [Sp] and [Sp-Rp-Sp] chimeric and stereo-random PS-oligos that contained a CpG motif showed higher cell proliferation than [Rp] PS-oligo of the same sequence. 相似文献
5.
Katsuyuki Aoki Ning-Hai Hu Tsutomu Tokuno Adegboye O. Adeyemo George N. Williams 《Inorganica chimica acta》1999,290(2):38-152
The reaction of thiamine with K2PtIICl4 and with PtIVCl4 in the presence of excess NaSCN in aqueous solution gave thiamine salts, (H-thiamine)[Pt(SCN)4] · 3H2O (1) and (H-thiamine)[Pt(SCN)6] · H2O (2), respectively, structures of which have been determined by X-ray diffraction. The thiamine molecule adopts the usual F conformation in each salt. In 1, [Pt(SCN)4]2− ions act as large planar spacers in the crystal lattice and interact scarcely with thiamine, except for a hydrogen bonding with the terminal hydroxy O(5γ). Instead, water molecules form two types of host–guest-like interactions with the pyrimidine and the thiazolium moieties of a thiamine molecule, one being a C(2)–Hwaterpyrimidine bridge and the other being an N(4′)–Hwaterthiazolium bridge. In 2, despite the much larger ion size, octahedral [Pt(SCN)6]2− ions form a C(2)–Hanionpyrimidine bridge and an N(4′)–Hanionthiazolium bridge. An additional hydrogen bonding between the anion and the terminal O(5γ) of thiamine creates a hydrogen-bonded macrocyclic ring {thiaminium–[Pt(SCN)6]2−}2, a supramolecule. 相似文献
6.
William Henderson Brian K. Nicholson Sarah M. Devoy T.S. Andy Hor 《Inorganica chimica acta》2008,361(7):1908-1914
The cationic monoalkylated derivatives of the well-known metalloligand [Pt2(μ-S)2(PPh3)4], viz. [Pt2(μ-S)(μ-SR)(PPh3)4]+ (R = n-Bu, CH2Ph) are themselves able to act as metalloligands towards the Ph3PAu+ and R′Hg+ (R′ = Ph or ferrocenyl) fragments, by reaction with Ph3PAuCl or R′HgCl, respectively. The resulting dicationic products [Pt2(μ-SR)(μ-SAuPPh3)(PPh3)4]2+ and [Pt2(μ-SR)(μ-SHgR′)(PPh3)4]2+ are readily isolated as their hexafluorophosphate salts, and have been fully characterised by spectroscopic techniques and an X-ray structure determination on [Pt2(μ-SR)(μ-SHgFc)(PPh3)4](PF6)2. 相似文献
7.
Alzir A. Batista Edna A. Polato Salete L. Queiroz Otaciro R. Nascimento Brian R. James Steven J. Rettig 《Inorganica chimica acta》1995,230(1-2):111-117
Complexes RuCl3(PPh3)L2 (L = MeIm (1a, Im (1b)) and [RuCl2(PPh3)2(bipy)]Cl·4H2O (2) have been synthesized via the ruthenium(III) precursor RuCl3(PPh3)2 (DMA), and characterized, including an X-ray structural analysis for 1a (MeIm = N-methylimidazole, Im = imidazole, bipy = 2,2′-bipyridyl, and DMA = N, N′-dimethylacetamide). Crystals of 1a are monoclinic, space group P21/n, A = 10.5491(5), B = 20.4934(9), C = 12.8285(4) Å, β = 90.166(4)°, Z = 4. The structure, which reveals a mer configuration for the chlorides, and cis-methylimidazoles, was solved by conventional heavy atom methods and was refined by full-matrix least-square procedures to R = 0.041 and Rw = 0.042 for 3328 reflections with I 3σ(I). From the RuCl2(PPh3)3 precursor, the ruthenium(II) complexes RuCl2(PPh3)2L2 and [RuCl(PPh3)L4]Cl have been made (L = Im or MeIm), while [RuCl(dppb)Im3]Cl has been made from [RuCl2(dppb)]2(μ-dppb) (dppb = Ph2P(CH2)4PPh2). 相似文献
8.
Synthesis of non-immunosuppressive cyclophilin-Binding cyclosporin A derivatives as potential anti-HIV-1 drugs 总被引:1,自引:0,他引:1
Evers M Barrière JC Bashiardes G Bousseau A Carry JC Dereu N Filoche B Henin Y Sablé S Vuilhorgne M Mignani S 《Bioorganic & medicinal chemistry letters》2003,13(24):4415-4419
Original cyclosporin A (CsA) derivatives bearing various alkylthio side chains at the sarcosine residue 3 (R configuration) and for the most potent and selective compounds a 4′-hydroxyl group at the Me-Leucine residue 4 were prepared in one or two steps from commercially available CsA. The [2-(dimethyl or diethylamino)-ethylthio-Sar]3-[(4′-OH)MeLeu]4-CsA derivatives 3k and 3l displayed potent in vitro anti-HIV-1 (IC50 46 nM) and low immunosuppressive activities (IC50≥1500 nM). 相似文献
9.
Tsuyoshi Suganuma Atsushi Tanada Hiroshi Tomizawa Mikio Tanaka Eiichi Miki 《Inorganica chimica acta》2001,320(1-2):22-30
The relationship between the pKa of 8-quinolinol derivatives {8-quinolinol (Hqn), 2-methyl- (H2-Meqn), 2,4-dimethyl- (H2,4-diMeqn), 5-chloro- (H5-Clqn) and 5,7-dichloro-8-quinolinols (H5,7-diClqn)} and a π-donor ability of the 8-quinolinolato oxygens has been investigated by the identification of the structures of the major products, [RuCl(QN)(QN′)NO] (HQN=8-quinolinol derivative; HQN′=different 8-quinolinol derivatives), obtained by the reaction of [RuCl3(QN or QN′)NO]− with HQN′ or HQN. The results obtained clearly showed that the oxygen of the 8-quinolinol derivative that has a higher pKa predominantly coordinates in the trans position to the NO ligand and is a better π-electron donor. The order of the π-electron donor ability for the oxygen of the 8-quinolinol derivatives is as follows: H2-Meqn≥H2,4-diMeqn>Hqn≥H5-Clqn>H5,7-diClqn, almost agreeing with the magnitude of the pKa values of the corresponding 8-quinolinols. The structures of cis-1 [RuCl(5,7-diClqn)2NO] and cis-1 [RuCl(5,7-diClqn)(2-Meqn)NO] were determined by X-ray diffraction. 相似文献
10.
Edwin C. Constable Catherine E. Housecroft Markus Neuburger Silvia Schaffner Ellen J. Shardlow 《Inorganica chimica acta》2007,360(15):4069-4076
The heteroditopic ligand 4′-(4,7,10-trioxadec-1-yn-10-yl)-2,2′:6′,2″-terpyridine, 2, contains an N,N′,N″-donor metal-binding domain that recognizes iron(II), and a terminal alkyne site that selectively couples to platinum(II). This selectivity has been used to investigate routes to the formation of heterometallic systems. The single crystal structures of ligand 2 and the complex [Fe(2)2][PF6]2 are reported. 相似文献
11.
J Mari?o-Albernas V Verez-Bencomo L Gonzalez-Rodriguez C S Perez-Martinez E Gonzalez-Abreu Castell A Gonzalez-Segredo 《Carbohydrate research》1988,180(2):175-182
The crystal and the molecular structure of 4,1′,6′-trichloro-4,1′,6′-trideoxy-galacto-sucrose (TGS) was determined by X-ray analysis at 294 K. Crystals of TGS are orthorhombic, space group P212121, with a = 7.318(3), b = 12.027(4), c = 18.136(5) Å, V = 1596(1) Å3, Z = 4; Dx = 1.655 g.cm-3, λ(MoK) = 0.71073 Å, μ(MoK) = 5.44 cm-1, F(000) = 816. The X-ray intensities of 2649 reflections with I 2.5σ(I) were measured with Zr-filtered MoK-radiation. The structure was solved by the Patterson procedure and refined by full-matrix least-squares to a final R-value of 0.0298. Large conformational differences between TGS and sucrose were observed, particularly in the conformation of the glycosidic linkage. These differences originate from chlorine substitution, which affects intramolecular hydrogen bonding and sweet-taste glucophores. 相似文献
12.
Kling A Lange UE Mack H Bakker MH Drescher KU Hornberger W Hutchins CW Möller A Müller R Schmidt M Unger L Wicke K Schellhaas K Steiner G 《Bioorganic & medicinal chemistry letters》2005,15(24):5567-5573
Novel 5-HT1 autoreceptor ligands based on the N-4-aryl-piperazinyl-N′-ethyl-5,6,7,8-tetrahydropyrido[4′, 3′:4,5]thieno[2,3-d]pyrimidin-4(3H)-one core are described. Aiming at antidepressants with a novel mode of action our objective was to identify potent antagonists showing balanced affinities and high selectivity for the 5-HT1A and 5-HT1B receptors. Strategies for the development of dual 5-HT1A and 5-HT1B antagonists based on 1 and 2 as leads and the corresponding results are discussed. Isoquinoline analogue 33 displayed high affinity and an antagonistic mode of action for the 5-HT1A and the 5-HT1B receptors and was characterized further with respect to selectivity, electrically stimulated [3H]5-HT release and in vivo efficacy. 相似文献
13.
van der Woude H Boersma MG Alink GM Vervoort J Rietjens IM 《Chemico-biological interactions》2006,160(3):193-203
This study investigates the pro-oxidant activity of 3′- and 4′-O-methylquercetin, two relevant phase II metabolites of quercetin without a functional catechol moiety, which is generally thought to be important for the pro-oxidant activity of quercetin. Oxidation of 3′- and 4′-O-methylquercetin with horseradish peroxidase in the presence of glutathione yielded two major metabolites for each compound, identified as the 6- and 8-glutathionyl conjugates of 3′- and 4′-O-methylquercetin. Thus, catechol-O-methylation of quercetin does not eliminate its pro-oxidant chemistry. Furthermore, the formation of these A-ring glutathione conjugates of 3′- and 4′-O-methylquercetin indicates that quercetin o-quinone may not be an intermediate in the formation of covalent quercetin adducts with glutathione, protein and/or DNA. In additional studies, it was demonstrated that covalent DNA adduct formation by a mixture of [4-14C]-3′- and 4′-O-methylquercetin in HepG2 cells amounted to only 42% of the level of covalent adducts formed by a similar amount of [4-14C]-quercetin. Altogether, these results reveal the effect of methylation of the catechol moiety of quercetin on its pro-oxidant behavior. Methylation of quercetin does not eliminate but considerably attenuates the cellular implications of the pro-oxidant activity of quercetin, which might add to the mechanisms underlying the apparent lack of in vivo carcinogenicity of this genotoxic compound. The paper also presents a new mechanism for the pro-oxidant chemistry of quercetin, eliminating the requirement for formation of an o-quinone, and explaining why methylation of the catechol moiety does not fully abolish formation of reactive DNA binding metabolites. 相似文献
14.
Atsushi Miyagawa Hidehiro Kurosawa Toshiyuki Watanabe Tetsuo Koyama Daiyo Terunuma Koji Matsuoka 《Carbohydrate polymers》2004,57(4):441-450
As an artificial ligand, a glycoconjugate polymer carrying carbohydrate moiety of lactosyl ceramide or globotriaosyl ceramide (Gb3) was synthesized. Gb3 is known as the receptor of Shiga toxin-producing Escherichia coli O157: H7. The preparation of the glycoconjugate polymer initially involves the construction of the carbohydrate moiety of Gb3 derivative which has n-pentenyl group as polymerizable group. In addition, the n-pentenyl group of the Gb3 derivative was modified and different polymerizable groups such as acrylamide group were introduced at ω-position of the aglycon. Radical polymerization of the synthesized glycosyl monomers with or without acrylamide proceeded smoothly in water using ammonium persulfate and N, N, N′, N′-tetramethylethylenediamine as usual initiator system and gave water-soluble glycoconjugate polymers having various polymer compositions. These polymers have the potential to neutralize Shiga toxin by reason of cluster effect and multivalency. 相似文献
15.
16.
Susan Stanislav Alguindigue Masood A. Khan Michael T. Ashby 《Inorganica chimica acta》2000,310(2):3297-162
The unique ligands of [Ru(bipy)2(bpda)](PF6)2 (1, BPDA=1,1′-biphenyl-2,2′-diamine) and [Ru(bipy)2(dabipy)](PF6)2 (2, DABIPY=3,3′-diamino-2,2′-bipyridine) are atropisomeric (exhibit hindered rotation about the sigma bonds that connect the two aromatic groups), so the complexes are diasteromeric with conformation isomers possible for the atropisomeric ligands and configurational isomers possible at the metal centers. Only one diastereomer is observed in the solid-state in both cases. The seven- (1) and five-membered (2) chelate ring of dabipy and bpda (the ligand is bound through its pyridyl groups) ligands are δ when the configuration at the metal is Δ. No evidence for atropisomerization is found in solution. For 1, we conclude bpda binds stereospecifically; however, the atropisomerization barrier of dabipy may be sufficiently low for 2 to preclude the observation of diastereomers by low-temperature NMR spectroscopy. 相似文献
17.
A number of highly purified polychlorinated biphenyl (PCB) isomers and congeners were synthesized and administered to male Wistar rats at dosage levels of 30 and 150 μmol · kg−1. The effects of this in vivo treatment on the drug-metabolizing enzymes were determined by measuring the microsomal benzo[a]pyrene (B[a]P) hydroxylase, dimethylaminoantipyrine (DMAP) N-demethylase and NADPH-cytochrome c reductase enzyme activities, the cytochrome b5 content and the relative peak intensities and spectral shifts of the reduced microsomal cytochrome P-450: CO and ethylisocyanide (EIC) binding difference spectra. The results were compared to the effects of administering phenobarbitone (PB), 3-methylcholanthrene (MC) and PB plus MC (coadministered) to the test animals. The synthetic PCB congeners used in this study included 3,4,4′,5-tetrachlorobiphenyl (TCBP-1), 2,3′,4,4′-tetrachlorobiphenyl (TCBP-2), 2,3′,4,4′,5′-pentachlorobiphenyl (PCBP-1), 2,3,4,4′,5-pentachlorobiphenyl (PCBP-2), 2,3,3′,4,4′,5-hexachlorobiphenyl (HCBP-1), 2,3,3′,4′,5,6-hexachlorobiphenyl (HCBP-2), 2,3,3′,5,5′,6-hexachlorobiphenyl (HCBP-3), 2,2′,3,5,5′,6-hexachlorobiphenyl (HCBP-4) and 2,3,3′,4,5,5′-hexachlorobiphenyl (HCBP-5) and were used to reappraise the structure-activity rules for PCBs as hepatic microsomal enzyme inducers. The results suggested that (a) PCBs which induce MC or mixed-type activity must be substituted at both para positions, at least two meta positions but not necessarily on the same phenyl ring and can also contain one ortho chloro substituent; (b) due to the considerable structural diversity of the PB-type inducers the rules for induction of this activity by PCB congeners are not readily defined. 相似文献
18.
K Yagawa M Nakanishi S Hayashi M Kaku Y Ichinose T Itoh A Tomoda Y Yoneyama N Shigematsu 《FEBS letters》1986,200(2):287-290
DNA-dependent RNA polymerase B (II) from wheat germ was modified by incubation with 4-[N-(β-hydroxyethyl)-N-methyl]benzaldehyde esters of AMP, ADP or ATP, followed by reduction with NaBH4. Reaction of the modified enzyme with [-32P]UTP in the presence of various DNA templates led to a highly selective affinity labelling of the subunit with Mr 140000 by covalently linked ApU. Labelling was inhibited by 1μg/ml -amanitin. 相似文献
19.
Marc Lutz Wojciech Szponarski G rard Berger Bruno Robert Jean-Michel Neumann 《BBA》1987,894(3):423-433
In order to solve discrepancies between earlier assignments we have reinvestigated the stereoisomerism of the spheroidene molecule bound to reaction centers (RC) of Rhodobacter sphaeroides. A stable cis isomer could be extracted and purified from the reaction centres by working at very low ambient light. Resonance Raman spectroscopy showed that this cis isomer assumed the same configuration as that of the RC-bound molecule. Proton-NMR spectroscopy of the extracted isomer permitted to assign it the 15–15′ mono cis configuration. Comparisons between resonance Raman spectra of the native form and of the 15 cis extract showed that, in the reaction center, 15 cis spheroidene is in addition twisted into a non-planar conformation. Comparisons of extraction-induced changes in relative intensities of Raman bands of the 760–1060 cm−1 regions, which largely correspond to out-of-plane modes, further indicated that the out-of-plane twist of RC-bound spheroidene should predominantly affect C8–C12 and/or C8′–C12′ regions of the molecule rather than the central region. Comparisons between difference electronic absorption spectra of RC-bound spheroidene and of RC-bound methoxyneurosporene showed that the out-of-plane twisting of both these native forms results in a drastic weakening of their 1C ← 1A electronic transitions, compared with those of the planar, 15 cis forms. Finally, it is proposed, on the basis of their resonance Raman spectra, that spirilloxanthin bound to RCs of Rhodospirillum rubrum as well as dihydroneurosporene or dihydrolycopene bound to RCs of Rhodopseudomonas viridis shares 15 cis configurations and out-of-plane twisting with carotenoids bound to RCs of various strains of Rb. sphaeroides. 相似文献
20.
Jian-Qing Tao Zhi-Guo Gu Tian-Wei Wang Qiao-Fang Yang Jing-Lin Zuo Xiao-Zeng You 《Inorganica chimica acta》2007,360(15):4125-4132
Two new spin-crossover complexes, [Fe(Medpq)(py)2(NCS)2] · py · 0.5H2O (1) and [Fe(Medpq)(py)2(NCSe)2] · py (2) (Medpq = 2-methyldipyrido[3,2-f:2′,3′-h]-quinoxaline, py = pyridine), have been synthesized. The crystal structures were determined at both room temperature (298 K) and low temperature (110 K). Complexes 1 and 2 crystallize in the orthorhombic space group Pbca and monoclinic space group P21/n, respectively. In both complexes, the distorted [FeN6] octahedron is formed by six nitrogen atoms from Medpq, the trans pyridine molecules and the cis NCX− groups. The thermal spin transition is accompanied by the shortening of the mean Fe–N distances by 0.194 Å for 2. The mononuclear [Fe(Medpq)(py)2(NCS)2] and [Fe(Medpq)(py)2(NCSe)2] neutral species interact each other via π-stacking, resulting in a one-dimensional extended structure for both 1 and 2. There exist C–HX (X = S, Se) hydrogen bonds for both complexes. Variable-temperature magnetic susceptibility measurements and Mössbauer spectroscopy reveal the occurrence of a gradual spin transition. The transitions are centered at T1/2 = 120 K for 1 and T1/2 = 180 K for 2, respectively. 相似文献