The reactions of the half-sandwich iron(II) complex [FeCl(Cp*)(tmeda)] (1; Cp*=η(5)-C(5)Me(5), TMEDA=N,N,N',N'-tetramethylethylenediamine) with potassium naphthalenide or potassium anthracenide gave the diamagnetic complexes [(Cp*)Fe(μ-polyarene)Fe(Cp*)] (polyarene=naphthalene (2), anthracene (3a)), which have two {(Cp*)Fe} units bound to opposite faces of the polyarene. One of two {(Cp*)Fe} units in 3a is located over the central ring of anthracene while the other is positioned over an outer ring. The {(Cp*)Fe} unit bound to the central ring of 3a migrates to the outer ring upon heating in the solid state to give the isomer 3b.
View Article and Find Full Text PDFHigh-yield synthesis of the iron-sulfur cluster [{N(SiMe(3))(2)}{SC(NMe(2))(2)}Fe(4)S(3)](2)(mu(6)-S) {mu-N(SiMe(3))(2)}(2) (1), which reproduces the [8Fe-7S] core structure of the nitrogenase P(N)-cluster, has been achieved via two pathways: (1) Fe{N(SiMe(3))(2)}(2) + HSTip (Tip = 2,4,6-(i)Pr(3)C(6)H(2)) + tetramethylthiourea (SC(NMe(2))(2)) + elemental sulfur (S(8)); and (2) Fe(3){N(SiMe(3))(2)}(2)(mu-STip)(4) (2) + HSTip + SC(NMe(2))(2) + S(8). The thiourea and terminal amide ligands of 1 were found to be replaceable by thiolate ligands upon treatment with thiolate anions and thiols at -40 degrees C, respectively, and a series of [8Fe-7S] clusters bearing two to four thiolate ligands have been synthesized and their structures were determined by X-ray analysis. The structures of these model [8Fe-7S] clusters all closely resemble that of the reduced form of P-cluster (P(N)) having 8Fe(II) centers, while their 6Fe(II)-2Fe(III) oxidation states correspond to the oxidized form of P-cluster (P(OX)).
View Article and Find Full Text PDFWe have developed a new time-resolved fluorometric (TRF) microarray detection system consisting of fluorescent NH2 nanosphere, TRF microarray detector and gamma-irradiated polystyrene chip. Using the TRF microarray detector, we detected 500 particles of the fluorescent nanosphere in one channel. Cross-talk fluorescence from the adjacent channels was little observed in the TRF microarray detector (<0.
View Article and Find Full Text PDFThe variable temperature magnetic susceptibility, X-ray crystallography, and Mössbauer and Raman spectra of a new dinuclear complex-based one-dimensional coordination polymer [[Fe(II)2(NCS)2(mu-bpypz)2](micro-4,4'-bpy)].MeOH demonstrated a steep one-step [HS-HS] to [LS-LS] spin transition.
View Article and Find Full Text PDFThe [8Fe-7S] core of the P-clusters in nitrogenases is unique among the known [Fe-S] clusters which are essential to electron-transfer processes in nature. The [8Fe-7S] cluster has been thought unstable and to exist only in protein environments. We found that this unusual [8Fe-7S] structure can be self-assembled from the reaction of Fe(II) bis-amide, tetramethylthiourea, 2,4,6-triisopropylbenzenethiol, and elemental sulfur in a specific mole ratio.
View Article and Find Full Text PDFNovel intercalation compounds constructed from the common two-dimensional hydrogen-bond-supported layers and functional guests [(H(0.5)phz)(2)[Fe(CA)(2)(H(2)O)(2)].2H(2)O](n)(1), ([Fe(Cp)(2)][Fe(CA)(2)(H(2)O)(2)])(n)(2), ([Fe(Cp*)(2)][Fe(CA)(2)(H(2)O)(2)])(n)(3), and [(TTF)(2)[Fe(CA)(2)(H(2)O)(2)]](n)(4) (H(2)CA = chloranilic acid, phz = phenazine, [Fe(Cp)(2)] = ferrocene, [Fe(Cp*)(2)] = decamethylferrocene, TTF = tetrathiafulvalene) are described.
View Article and Find Full Text PDFA mixed-valence trinuclear iron cyanoacetate complex, [Fe(3)O(O(2)CCH(2)CN)(6)(H(2)O)(3)] (1), was prepared, and the nature of the electron-detrapping phase transition was studied by a multitemperature single-crystal X-ray structure determination (296, 135, and 100 K) and calorimetry by comparison with an isostructural mixed-metal complex, [CoFe(2)O(O(2)CCH(2)CN)(6)(H(2)O)(3)] (2). The mixed-valence states at various temperatures were also determined by (57)Fe Mössbauer spectroscopy. The Mössbauer spectrum of 1 showed a valence-detrapped state at room temperature.
View Article and Find Full Text PDFNew copper(II) intercalation compounds, {[Cu(CA)(H(2)O)(2)](G)}(n)() (H(2)CA = chloranilic acid; G = 2,5-dimethylpyrazine (dmpyz) (1a and 1b) and phenazine (phz) (2)) have been synthesized and characterized. 1acrystallizes in the triclinic space group P&onemacr;, with a = 8.028(2) Å, b = 10.
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