We recently described site-specific pyrene labeling of RNA to monitor Mg(2+)-dependent equilibrium formation of tertiary structure. Here we extend these studies to follow the folding kinetics of the 160-nucleotide P4-P6 domain of the Tetrahymena group I intron RNA, using stopped-flow fluorescence with approximately 1 ms time resolution. Pyrene-labeled P4-P6 was prepared using a new phosphoramid...

The reaction of Ln(AlMe(4))(3) with bulky hydrotris(pyrazolyl)borate (Tp(t)(Bu,Me))H proceeds via a sequence of methane elimination and C-H bond activation, affording unprecedented rare-earth metal ligand moieties including Ln(Me)[(micro-Me)AlMe(3)] and X-ray structurally characterized "Tebbe-like" Ln[(micro-CH(2))(2)AlMe(2)].

The mol-ecular structure of (acetone-κO)tris-(μ-ferrocene-1,1'-dicarbo-nitrile-κ(2) N:N')dicopper(I) bis-(tetra-fluorido-borate) acetone monosolvate, [Cu2Fe3(C6H4N)6(C3H6O)](BF4)2·C3H6O, consists of two Cu(I) ions bridged by a ferrocene-1,1'-dicarbo-nitrile moiety in a paddle-wheel-architectured sandwich complex with two BF4 (-) units as counter-ions. One of the latter is equally disordered ove...

The bidentate 1,3,4-thia-diazole ligand, namely, 2,5-bis-(2-pyrid-yl)-1,3,4-thia-diazole (denoted L), untested as a polydentate ligand, has been found to form the monomeric title complex, [Ni(C(12)H(8)N(4)S)(2)(H(2)O)(2)](BF(4))(2). The complex shows an octa-hedral environment of the nickel cation in which the Ni(2+) ion is located on a center of symmetry, linked to two ligands and two water mo...

Producing reliable electrical contacts of molecular dimensions has been a critical challenge in the field of molecule-based electronics. Conventional thin film deposition and photolithography techniques have been utilized to construct novel nanometer-sized electrodes on the exposed vertical plane on the edge of a thin film multilayer structure (metal/insulator/metal). Via thiol surface attachme...

The mononuclear nickel title complex (acetonitrile-κN){N-benzyl-N,N',N'-tris-[(6-methyl-pyridin-2-yl)meth-yl]ethane-1,2-di-amine}-nickel(II) bis-(tetra-fluor-ido-borate), [Ni(C30H35N5)(CH3CN)](BF4)2, was prepared from the reaction of Ni(BF4)2·6H2O with N-benzyl-N,N',N'-tris-[(6-methyl-pyridin-2-yl)meth-yl]ethane-1,2-di-amine (bztmpen) in aceto-nitrile at room temperature. With an open site occu...

Reaction of BI3 with carbodi-phospho-rane, C(PPh3)2, gives a mixture of the dicationic compounds, methyl-enebis(tri-phenyl-phospho-nium) diiodide di-chloro-methane disolvate, C37H32P22+·2I-·2CH2Cl2 or [Ph3PCH2PPh3]I2·2CH2Cl2 (I), methyl-enebis(tri-phenyl-phospho-nium) bis-(tetra-iodo-borate), C37H32P22+·2BI4- or [Ph3PCH2PPh3](BI4)2 (II). Solvents are the source of the protons at the ylidic C at...

The reaction of EuI2(THF)2 with potassium hydro-tris-(3,5-diiso-propyl-pyrazol-yl)borate (K[HB(3,5- iPr2pz)3] (= KTp iPr2, pz = pyrazol-yl) in a molar ratio of 1:1.5 resulted in extensive ligand fragmentation and formation of the europium(II) mono(scorpionate) complex bis-(3,5-diisopropyl-1H-pyrazole)[hydro-tris-(3,5-diiso-propyl-pyrazol-yl)borato]iodido-europium(II), [Eu(C27H46BN6)I(C9H16N2)2]...