共查询到20条相似文献,搜索用时 11 毫秒
1.
Hossein Chiniforoshan Jafar Mohammad Nezhad Amir H. Mahmoudkhani 《Inorganica chimica acta》2006,359(7):2101-2106
Several five coordinate complexes of [(TPP)FeIII(L)] in which TPP is the dianion of tetraphenylporphyrin and L is the monoanion of phenylcyanamide (pcyd) (1), 2,5-dichlorophenylcyanamide (2,5-Cl2pcyd) (2), 2,6-dichlorophenylcyanamide (2,6-Cl2pcyd) (3), and 2,3,4,6-tetrachlorophenylcyanamide (2,3,4,6-Cl4pcyd) (4) have been prepared by the reaction of [(TPP)FeIIICl] with appropriate thallium salt of phenylcyanamide. Each of the complexes has been characterized by IR, UV-Vis and 1H NMR spectroscopic data. Dark red-brown needles of [(TPP)FeIII(2,6-Cl2pcyd)] (C51H31Cl2FeN6 · CHCl3) crystallize in the triclinic system. The crystal structure of Fe(III) compound shows a slight distortion from square pyramidal coordination with the 2,6-dichlorophenylcyanamide anion in the axial position through nitrile nitrogen atom. Iron atom is 0.47(1) Å out of plane of the porphyrin toward phenylcyanamide ligand. In non-coordinating solvents, such as benzene or chloroform, these complexes exhibit 1H NMR spectra that are characteristic of high-spin (S = 5/2) species. The X-ray crystal structure parameters are also consistent with high-spin iron(III) complexes. The iron(III) phenylcyanamide complexes are not reactive toward molecular oxygen; however, these complexes react with HCl and produce TPPFeIIICl. 相似文献
2.
Pengfei Shi Qin Jiang Yongmei Zhao Yangmiao Zhang Jun Lin Liping Lin Jian Ding Zijian Guo 《Journal of biological inorganic chemistry》2006,11(6):745-752
Four gold(III) complexes of terpyridine derivatives 1–4 have been synthesized and characterized by spectroscopic methods. In vitro data demonstrated that all of them showed higher cytotoxicity than cisplatin against the human non-small-cell lung cancer cell line (A-549), the human stomach carcinoma cell line (SGC-7901), the human cervix carcinoma cell line (HELA), the human colon carcinoma cell line (HCT-116), the human liver carcinoma cell line (BEL-7402), the murine leukemia cell line (P-388) and the human acute promyelocytic leukemia cell line (HL-60). Complex 3 exhibits the highest activity, with growth inhibition rates of over 80% at 10−8 mol L−1 against the A-549, HCT-116 and HELA tumor cell lines. Interestingly, ligands L1–L4 are also very cytotoxic against the cell lines tested. Complexes 1–4 are stable in aqueous solution for 2 days in the presence of the biological reducing agent glutathione. The inductively coupled plasma mass spectrometry data showed that DNA isolated from cells treated with complexes 1 and 3 contained gold with gold-to-nucleotide ratios of approximately 1:6,400 and 1:4,900, respectively. Fluorescence titration, UV and circular dichroism analyses proved that the steric and electrostatic effects of the ligand remarkably influence the interactions of their gold(III) complexes with DNA. The DNA binding ability of the complexes has been correlated with their cytotoxicity, which could potentially provide a new rationale for the future design of terpyridine-based metal complexes with antitumor potential.Electronic Supplementary Material Supplementary material is available to authorized users in the online version of this article at . 相似文献
3.
Transmetallation reactions of ortho-mercurated iminophosphoranes (2-ClHgC6H4)Ph2PNR with [AuCl4]− gives new cycloaurated iminophosphorane complexes of gold(III) (2-Cl2AuC6H4)Ph2PNR [R = (R,S)- or (S)-CHMePh, p-C6H4F, tBu], characterised by NMR and IR spectroscopies, ESI mass spectrometry and an X-ray structure determination on the chiral derivative R = (S)-CHMePh. The chloride ligands of these complexes can be readily replaced by the chelating ligands thiosalicylate and catecholate; the resulting derivatives show markedly higher anti-tumour activity versus P388 murine leukaemia cells compared to the parent chloride complexes. Reaction of (2-Cl2AuC6H4)Ph2PNPh with PPh3 results in displacement of a chloride ligand giving the cationic complex [(2-Cl(PPh3)AuC6H4)Ph2PNPh]+, indicating that the PN donor is strongly bonded to the gold centre. 相似文献
4.
Nasser Safari Behrouz Notash Hossein Chiniforoshan Ali R. Rezvani 《Inorganica chimica acta》2005,358(11):2967-2974
Several complexes of TPPMn-L, where TPP is the dianion of tetraphenylporphyrin and L is monoanion of 4-methylphenylcyanamide (4-Mepcyd) (1), 2,4-dimethylphenylcyanamide (2,4-Me2pcyd) (2), 3,5-dimethylphenylcyanamide (3,5-Me2pcyd) (3), 4-methoxyphenylcyanamide (4-MeOpcyd) (4), phenylcyanamide (pcyd) (5), 2-chlorophenylcyanamide (2-Clpcyd) (6), 2,5-dichlorophenylcyanamide (2,5-Cl2pcyd) (7), 2,6-dichlorophenylcyanamide (2,6-Cl2pcyd) (8), 4-bromophenylcyanamide (4-Brpcyd) (9), and 2,3,4,5-tetrachlorophenylcyanamide (2,3,4,5-Cl4pcyd) (10), have been prepared from the reaction of TPPMnCl and thallium salt of related phenylcyanamide. Each of the complexes has been characterized by IR, UV-Vis and 1H NMR spectroscopies.4-Methylphenylcyanamidotetraphenylporphyrin manganese(III) crystallized with one molecule of solvent CHCl3 in the triclinic crystal system and space group with the following unit cell parameters of: a = 11.596(6) Å; b = 11.768(9) Å; c = 17.81(2) Å; and α, β, γ are 88.91(9)°, 88.16(7)°, 67.90(5)°, respectively; V = 2251(3) Å3; Z = 2. A total of 4234 reflections with I > 2σ(I) were used to refine the structure to R = 0.0680 and Rw = 0.2297. The Mn(III) shows slightly distorted square pyramidal coordination with the 4-methylphenylcyanamide in the axial position, coordinated from nitrile nitrogen. The reduction of each of the TPPMn-L complexes was also examined in dichloromethane and spectroelectrochemical behavior of (1) was investigated and compared to TPPMnCl. 相似文献
5.
Hua-Fen Hsu Wan-Yu Peng Ru-Rong Wu Yu Wang Minghuey Shieh 《Inorganica chimica acta》2005,358(6):2149-2154
The synthesis and crystal structures of two high valent molybdenum complexes containing trisbenzenethiolatophosphine ligands, [Mo2(PS3)2(PS3H)] (1) and [Mo(PS3″)2] (2), where PS3 = [P(C6H4-2-S)3]3−, PS3H = [P(C6H4-2-S)2(C6H4-2-SH)]2−, and PS3″ = [P(C6H3-3-Me3Si-2-S)3]3−, are described. Compound 1 is a dimeric Mo(IV) species containing three PS3 ligands with an uncoordinated thiol group. An intramolecular hydrogen bonding S-H?S was found in the structure. Two molybdenum ions are bridged by three thiolates. The geometry can be described as two pentagonal bipyramids sharing a triangle face formed by three bridging S atoms. Compound 2 is a Mo(VI) species binding with two tetradentate PS3″ ligands. The eight-coordinate molybdenum center adopts a dodecahedral geometry. 相似文献
6.
A series of Rh(III) mixed ligand polypyridine type complexes have been prepared. Complexes of the form [Rh(L)2(L′)]n+, where n=2/3, L=2,2′-bipyridine (bpy)/1,10-phenanthroline (phen) and L′=3-(pyridin-2-yl)-1,2,4-triazole (Hpytr), 1-methyl-3-(pyridin-2-yl)-1,2,4-triazole (1M3pytr), 4-methyl-3-(pyridin-2-yl)-1,2,4-triazole (4Mpytr), 3,5-bis(pyridin-2-yl)-1,2,4-triazole (Hbpt), 4-amino-3,5-bis(pyridin-2-yl)-1,2,4-triazole (NH2bpt) and 3-(pyridin-2-yl)-5-phenyl-1,2,4-triazole (HPhpytr), have been prepared and their synthesis and characterisation are reported. Crystals of [Rh(bpy)2(Phpytr)](PF6)2 and [Rh(phen)2(NHbpt)](PF6)2 were obtained and their structures determined. Analysis of X-ray crystallographic data showed that coordination of the metal centre in [Rh(phen)2(NHbpt)](PF6)2 occurs via the amine moiety and a nitrogen of the pyridine ring. NMR studies illustrated that coordination to the NH2bpt ligand was also possible via a nitrogen of the triazole ring and the pyridine ring forming the complex [Rh(phen)2(NH2bpt)](PF6)3. The absorption and emission properties of the complexes studied were found to be π-π* in nature and preliminary evidence suggests that all complexes with the exception of [Rh(phen)2(NHbpt)](PF6)2 and [Rh(bpy)2(NHbpt)](PF6)2 are dual emitting at 77 K. 相似文献
7.
Six antimony adducts with N-donor neutral ligands (1,10-phenanthroline, 4,4′-bipyridine) have been obtained following the reaction of antimony halides with phenanthroline and 4,4′-bipyridine. By changing the solvent and stoichiometry, we obtained six different complexes, Sb(phen)Cl3 (1), Sb(phen)Br3 (2), Sb2(phen)4Br8 (3) and Sb(bpy)Cl3 (4), Sb(bpy)2Cl3 (5), Sb(bpyH · bpyH2)Br6 (6) (where phen = 1,10-phenanthroline, bpy = 4,4′-bipyridine). All the complexes have been characterized via elemental analysis, FT-IR and NMR (1H, 13C) spectroscopy. The crystal structures of complexes 2, 3 and 6 have been determined by X-ray single crystal diffraction.The structural analysis show that the coordination sphere around antimony atom in complex 2 is a distorted square pyramid, coordinated by three bromine atoms and two nitrogen atoms from phen. In complex 3, the central antimony atom is six-coordinated through four bromine atoms and two nitrogen atoms forming a distorted octahedral geometry. Besides that, there are also uncoordinated 1,10-phenanthroline bonded by hydrogen bonds and π-π stacking interactions, which is rarely observed in previous reports. The crystal structure of complex 6 consists of bpyH · bpyH2 trications and hexabromoantimonate trianions. The antimony atom in the anion has a distorted octahedral environment. Additionally, all complexes present a 3D framework built up by N-H?Br, C-H?Br and C-H?Cl weak hydrogen bonds interactions. 相似文献
8.
Aleksander Kufelnicki Stefania V. Tomyn Matti Haukka Jan Jaszczak Igor O. Fritsky 《Inorganica chimica acta》2010,363(12):2996-3003
Cobalt(III) complexes with new open chain oxime ligands: N,N′-bis(2-hydroxyiminopropionyl)-1,2-aminoethane (H2pen) and N,N′-bis(2-hydroxyiminopropionyl)-1,3-diaminopropane (H2pap) have been investigated. Single crystals of Co(papH−1)(Im2)·CH3OH (1) and Co(papH−1)(MEA)2·1.5H2O (2) (where Im = imidazole, MEA = monoethanolamine) suitable for X-ray crystallography were grown by slow evaporation of methanol/water solutions at room temperature. The molecular structures have been determined using single-crystal X-ray diffraction methods. The potentiometric and spectrophotometric results in aqueous solution reveal that both of the open chain ligands show a very high efficacy in the coordination of Co(II) ions. As it has been indicated, differences between the two oxime ligands in complexing ability may be attributed to the longer -CH2- chain in H2pap and by that a better fit of the relatively large Co(II) ion to the accessible binding site. One of the complex species confirmed under inert atmosphere, namely of type Co(LH−1)− (where L = pap or pen), has been shown as the “active” form, capable of dioxygen uptake followed by irreversible oxidation to Co(III). 相似文献
9.
Iwona ?akomska Bo?enna Golankiewicz Marzena Pe?czyńska Adam Opolski Lech Kozerski 《Inorganica chimica acta》2005,358(6):1911-1917
A series of platinum(II) complexes with 6,8-dimethylimidazo[1,5-a]-1,3,5-triazin-4(3H)-one (6,8-DiMe-4-O-IMT) (I) and 6,8-dimethyl-2-thioxo-2,3-dihydroimidazo[1,5-a]-1,3,5-triazin-4(1H)-one (6,8-DiMe-4-O-2-S-IMT) (II) of formula trans-[PtCl2(dmso)(6,8-DiMe-4-O-IMT)] (1a) and trans-[PtCl2(dmso)(6,8-DiMe-4-O-2-S-IMT)] (2a) have been prepared and characterized with 1H, 13C, 15N, 195Pt NMR and IR. Significant 15N NMR upfield coordination shifts (81-96 ppm) of N(7) atom indicate this nitrogen atom as a coordination site. The multinuclear NMR and IR spectra indicate the square planar geometry with N(7) bonded heterocycles, S-bonded dimethylsulfoxide and two trans chloride anions. The platinum(II) complexes were tested for their antiproliferative activity in vitro against the cells of four human cell lines: SW707 rectal adenocarcinoma, A549 non-small cell lung carcinoma, T47D breast cancer and HCV29T bladder cancer. The activity of (1a, 2a) was lower than that of cisplatin. 相似文献
10.
Florence J. MonlienLothar Helm Amira Abou-HamdanAndré E. Merbach 《Inorganica chimica acta》2002,331(1):257-269
Kinetic studies of X− exchange on [AuX4]− square-planar complexes (where X=Cl− and CN−) were performed at acidic pH in the case of chloride system and as a function of pH for the cyanide one. Chloride NMR study (330-365 K) gives a second-order rate law on [AuCl4]− with the kinetic parameters: (k2Au,Cl)298=0.56±0.03 s−1 mol−1 kg; ΔH2‡ Au,Cl=65.1±1 kJ mol−1; ΔS2‡ Au,Cl=−31.3±3 J mol−1 K−1 and ΔV2‡ Au,Cl=−14±2 cm3 mol−1. The variable pressure data clearly indicate the operation of an Ia or A mechanism for this exchange pathway. The proton exchange on HCN was determined by 13C NMR as a function of pH and the rate constant of the three reaction pathways involving H2O, OH− and CN− were determined: k0HCN,H=113±17 s−1, k1HCN,H=(2.9±0.7)×109 s−1 mol−1 kg and k2HCN,H=(0.6±0.2)×106 s−1 mol−1 kg at 298.1 K. The rate law of the cyanide exchange on [Au(CN)4]− was found to be second order with the following kinetic parameters: (k2Au,CN)298=6240±85 s−1 mol−1 kg, ΔH2‡ Au,CN=40.0±0.8 kJ mol−1, ΔS2‡ Au,CN=−37.8±3 J mol−1 K−1 and ΔV2‡ Au,CN=+2±1 cm3 mol−1. The rate constant observed varies about nine orders of magnitude depending on the pH and HCN does not act as a nucleophile. The observed rate constant of X− exchange on [AuX4]− are two or three orders of magnitude faster than the Pt(II) analogue. 相似文献
11.
The reactions of a self-assembled silver(I) coordination polymer, [Ag2{μ-PriN(PPh2)2}(μ-NO3)2]n (1) with various bidentate N-donor ligands such as DABCO, 2,2′-bipyridyl and 1,10-phenanthroline yield 1-D helices or π-π stacked polymers, depending on the chelate vector of the N-donor ligand. The molecular structures of the resultant complexes, [Ag2{μ-PriN(PPh2)2}(DABCO)(NO3)2]n (2), [Ag2{μ-PriN(PPh2)2}(2,2′-bipy)2(NO3)2] (3) and [Ag2{μ-PriN(PPh2)2}(1,10-phen)2](NO3)2 (4) have been confirmed by single-crystal X-ray diffraction. Complex 2 exists as an infinite helical polymer because of the exo-bidentate nature of DABCO. Complex 3 assumes a 2D grid motif as a result of intermolecular π-π stacking among adjacent bipyridine moieties. The phenanthroline complex 4 exhibits strong inter- and intramolecular π-π stacking interactions. 相似文献
12.
Kamalakannan Palanichamy 《Inorganica chimica acta》2006,359(1):44-52
This work reports the synthesis, characterization, and aqueous chemistry of a series of cytotoxic [Au(polypyridyl)Cl2]PF6 complexes {(where polypyridyl = dipyrido[3,2-f:2′,3′-h] quinoxaline (DPQ), dipyrido[3,2-a:2′,3′-c] phenazine (DPPZ) and dipyrido[3,2-a:2′,3′-c](6,7,8,9-tetrahydro) phenazine (DPQC))}. The crystal structure of [Au(DPQ)Cl2]PF6 was determined as example of the series and exhibits the anticipated square planar geometry common for d8 coordination complexes. The crystals of the complex belong to the space group P21/n with a = 7.624(2) Å, b = 18.274(5) Å, c = 14.411(14) Å, β = 98.03(3)°, and Z = 4. In 1H NMR studies of these compounds in the presence of aqueous buffer, all four complexes rapidly converted to the dihydroxy species [Au(polypyridyl)(OH)2] in a stepwise fashion. However, the [Au(polypyridyl)]3+ fragment believed to impart cytotoxicity in human ovarian cancer cell lines (A2780) remained intact and appeared stable for days. It was also noted that these Au(III) complexes were readily reduced in the presence of the common biological reducing agents, reduced glutathione and sodium ascorbate. How solution and redox stability may affect the biological activity of these novel Au(III) complexes is discussed. 相似文献
13.
Francisco Silva I.C. Santos António Sebastião Rodrigues Isabel Santos 《Journal of inorganic biochemistry》2010,104(5):523-532
Reactions of GaCl3 with pyrazole-containing ligands of the pyrazole-imine-phenol (HL1-HL3) or pyrazole-amine-phenol (HL4-HL6) types led to the synthesis of well-defined [GaL2]+ homoleptic complexes (1-6). Complexes 1-6 were characterized by elemental analysis, ESI-MS (electrospray ionization-mass spectrometry), IR and NMR spectroscopies, and in the case of Complex 1 also by X-ray diffraction analysis. In complexes 1-3, the pyrazole-imine-phenolate ligands act as monoanionic chelators that coordinate to the metal in a meridional fashion, while 4-6 contain monoanionic and facially coordinated pyrazole-amine-phenolate ligands. Complexes 1-3 have a greater stability in solution compared to 4-6, which have shown a more pronounced tendency to release the respective ancillary ligands. The cytotoxicity of 1-6 and of the respective ligands (HL1-HL6) was evaluated against human prostate cancer cells PC-3 and human breast cancer cells MCF-7. The substituents of the phenolate rings strongly influenced the cytotoxicity of the compounds. Complexes 3 and 6 that contain chloride substituents at the phenolate rings have shown the highest cytotoxicity, including in the cisplatin-resistant PC-3 cell line. The cytotoxic profile of 3 and 6 is very similar to the one displayed by the respective anchor ligands, respectively HL1 and HL6. The cytotoxic activity of 3 and 6 is slightly increased by the presence of transferrin, and both complexes provoke cell death mainly by induction of apoptotic pathways. 相似文献
14.
The reaction of AuCl3py with Na(pz∗) (pz∗ = pyrazolato, or substituted pyrazolato anion) yields stable dinuclear [cis-AuIIICl2(μ-pz∗)]2 complexes. In the presence of a base, the latter undergo reduction with concomitant transformation of the dinuclear -structure to trinuclear AuI, AuIII (containing trans AuIIICl2-centres) and species. 相似文献
15.
The zinc(II) coordination chemistry of a series of diphenyldipyrazolylmethane ligands was explored using 1H NMR and single crystal X-ray diffraction. Unsubstituted diphenyldipyrazolylmethane (dpdpm), diphenylbis(3-methylpyrazolyl)methane (dpdp′m), and diphenylbis(3,5-dimethylpyrazolyl)methane (dpdp″m) were reacted with Zn(NO3)2 to afford Zn(dpdpm)(NO3)2, Zn(dpdp′m)(NO3)2 and Zn(Pz″)2(NO3)2 where Pz″ = 3,5-dimethylpyrazole, respectively. All attempts to isolate Zn(dpdp″m)(NO3)2 with the intact dpdp″m ligand were unsuccessful due to decomposition of the ligand. These bidentate ligands support the formation of 1:1 ligand to metal complexes and structurally model the two histidine coordination mode common in zinc proteins. 相似文献
16.
The coordination ability of dipeptides l-tryptophyl-l-phenylalanine (H-Trp-Phe-OH) and l-tyrosyl-l-tryptophan (H-Tyr-Trp-OH) with Au(III) have been elucidated both in solid state and in solution by means of series of methods as UV, 1H and 13C NMR, conventional and linear-polarized IR-spectroscopic tool in solid-state, based on orientation technique as suspension in nematic liquid crystal, FAB-MS, TGV, DSC methods and elemental analysis. The structures of the Au(III)-complexes have been predicted theoretically by DFT calculations at B3LYP level of theory and Lanl2DZ (Au)/6-31+G(3df) (Cl, C, H) basis set. The last data are compared with IR-LD spectroscopic ones giving the experimental evidence of the structures of the complexes studied. The dipeptides interact as tridentate ligands in obtained mononuclear complexes via their -NH2, deprotonated N−-amide and -groups at molar ratio metal to ligand 1:1. One Cl− ion is joined to the Au(III) as terminal ligand, forming [AuIII(LH−1)Cl] species. A near to square-planar flat geometry of the chromophores AuN2OCl is yielded with maximal deviation of total planarity less than 0.9°. 相似文献
17.
New ammonium derivatives of peroxo-carboxylato molybdenum(VI) complexes of general formula (NH4)2[MoO(O2)2(HxL)] · nH2O with L=oxalate (ox), citrate (cit), tartrate (tart), glycolate (glyc) and malate (mal) and (NH4)2[MoO2(O2)(L)] with L=oxalate (ox) have been prepared and characterized on the basis of elemental and thermal analysis as well as by IR and 13C NMR spectroscopy. These last two spectroscopic methods have been used to suggest the coordination mode of the ligand in the complexes. The X-ray crystal structures of the compounds (NH4)2[Mo2O2(O2)2(OH)2(ox)2], (NH4)2[MoO(O2)2(ox)] and (NH4)2[MoO(O2)2(glyc)] · 0.5EtOH have been determined, all showing a sevenfold-coordinated Mo atom with bidentate peroxides and carboxylate ligands. 相似文献
18.
Crosslinked chitosan--preparation and characterization 总被引:3,自引:0,他引:3
Chitosan undergoes radical-induced depolymerization in the presence of potassium persulfate at 60 degrees C, leading to extensive crosslinking of the fragmented chains on subsequent cooling at 4 degrees C. As a result, a possible conformational change leading to higher crystallinity, as evidenced by IR, X-ray and 13C NMR was observed. 相似文献
19.
Three binuclear Co(III) complexes with 5,5′-(buta-1,3-diyne-1,4-diyl)bis(3-tert-butylcatechol) (L1), 5,5′-(2,5-dimethoxy-1,4-phenylene)bis(ethyne-2,1-diyl)bis(3-tert-butyl-catechol) (L2) and 5,5′-(4,4′-(buta-1,3-diyne-1,4-diyl)bis(2,5-dimethoxy-4,1-phenylene))bis(ethyne-2,1-diyl)bis(3-tert-butyl-catechol) (L3) have been prepared. The triple bond-containing L1, L2 and L3 ligands were synthesized by a cross-coupling reaction. These complexes were characterized by elemental analyses, electrochemical measurements, 1H NMR and UV-Vis spectra. In [Co2(bpy)4(L1)]2+, electrochemical oxidation of the complexes occurs at the bridges as two closely spaced one-electron couples. UV-Vis spectra reveal that chemical oxidation of [Co2(bpy)4(L1)]2+ using Ag+ occurs as a two-electron process forming [Co2(bpy)4(L1Cat,SQ)]3+ or [Co2(bpy)4(L1SQ,SQ)]4+. On the other hand, [Co2(bpy)4(L2)]2+ and [Co2(bpy)4(L3)]2+ exhibit different oxidation behavior under the same experimental conditions. In this report we discuss the role of the distance between the two metal atoms on the oxidative behavior of binuclear Co(III) complexes. 相似文献
20.
Donald J. Darensbourg Cesar G. Ortiz Damon R. Billodeaux 《Inorganica chimica acta》2004,357(7):2143-2149
The synthesis and solid-state characterization of iron(III) salen complexes bearing monodentate and bidentate anionic oxygen donor ligands are reported. The synthesis of Fe(salen)OPh (OPh=2,6-diphenylphenoxide) (1) was accomplished using Fe[N(Si(CH3)3)2]3 with one equivalent of H2salen and the corresponding phenol. The complex was isolated as a crystalline sample by the slow diffusion of pentane into a concentrated solution of 1 at −20 °C. The solid-state structure of complex 1 reveals distorted square pyramidal geometry about the iron metal center. Alternatively the preparation of Fe(salen) complex 2 bearing the anionic, bidentate acetylacetonate ligand in the axial position was accomplished by thermally replacing two acetylacetonate ligands in Fe(acac)3 with one equivalent of H2salen. The complex was isolated and crystallographically characterized using X-ray quality crystals formed via the aforementioned protocol. The metal center adopts a very distorted octahedral geometry, indicating a preference for the square pyramidal species which is typical of other iron salen derivatives. Unfortunately, 1 and 2 were found to be inactive in the copolymerization of CO2 and cyclohexene oxide to afford polycarbonate in the presence of a Lewis base (i.e., N-MeIm and PCy3). The μ-[Fe(salen)]2O (3) derivative was also isolated via the protonation of Fe(salen)(N(Si(CH3)3)2). The complex is relatively air stable, forming large, dark crystals over a short period of time at −20 °C. The solid-state structure reveals a nearly linear Fe-O-Fe bond angle, which is due to the electronic repulsions associated with the sterically encumbering tert-butyl groups on the salen framework. 相似文献