Revised structure for fumarofine,an indenobenzazepine type alkaloid

Fumarofine is not a spirobenzylisoquinoline. Rather, it is the first know reduced indenobensazepine alkaloid, and possesses the cis B/C fused structure $\text{7}$. Rearrangement of synthetic spirobensylisoquinoline $\text{12}$ using methanesulfonyl chloride furnished indenobensazepine $\text{14}$. Osmium tetroxide oxidation of $\text{14}$ gave cis-glysol $\text{15}$. O-Methylfumarofine ($\text{8}$) was then obtained through pyridinium chlorochromate oxidation of $\text{15}$.     

Recognition of flexible peptides in water by transition metal complexes

This paper describes the design, synthesis, and evaluation of transition metal complexes capable of recognizing flexible histidine-containing peptides in aqueous medium (25 mM HEPES buffer, pH = 7.0, 25 degrees C). When the pattern of metal ions on a complex matches with the pattern of histidine moieties on the peptide, strong interaction (K = 1.2 x 10(6) M-1) can be achieved. The complex was highly selective (> 200:1) in discriminating similar flexible peptides differing only by one glycine unit.     

Synthetic utility and mechanistic implications of the Fries rearrangement of hydroquinone diesters in boron trifluoride complexes

Reactions of boron trifluoride methyl and ethyl etherate complexes with hydroquinone diesters yield monomethyl and monoethyl derivatives of acetylhydroquinones. The use of sterically hindered boron trifluoride etherate complexes results in acetylhydroquinone derivatives. This procedure represents a one-step synthesis of acetylhydroquinone derivatives, important building blocks for a variety of synthetic applications.     

The photochemistry of proaporphines: a new route to the aporphines

Proaporphines undergo light catalyzed rearrangement. Pakistanamine ($\text{1}$) is thus converted into lumipakistanine ($\text{2}$), while pronuciferine ($\text{7}$) and N-acetylnorpronuciferine ($\text{8}$) afford the corresponding C-9 hydroxylated aporphines $\text{9}$ and $\text{10}$. Possible biogenetic schemes for the formation of C-8, C-9-, and C-8,9-substituted aporphines are presented.     

Thermodynamic studies on the recognition of flexible peptides by transition-metal complexes

Strong and selective binding to a trihistidine peptide has been achieved employing Cu(2+)-histidine interactions in aqueous medium (25 mM HEPES buffer, pH 7.0). When the pattern of cupric ions on a complex matched with the pattern of histidines on the peptide, a strong and selective binding was observed. UV-vis spectroscopic studies show that the cupric ions coordinate to the histidines of the peptides. Thermodynamic studies reveal that the binding process is enthalpy driven over the entire range of working temperature (25-40 degrees C). An enthalpy-entropy compensation effect was also observed.     

Self‐Assembled Heteroleptic Zn(II) Dithiocarbamate‐Based 2D‐Interwoven Supramolecular Giant Macrocycles and Their Redox Properties

This article presents a new heteroleptic Zn(II) dithiocarbamate ( 1 ) having molecules linked together via H···H and π···π interactions to form a giant hexanuclear macrocycle. These macrocycles are connected together through S···H interactions to offer a unique two‐dimensional cloth‐like interwoven architecture in the solid state. The redox behavior of the complex deposited on the surface of a glassy carbon electrode was investigated in different pH media. The analyte was found to oxidize and reduce in a pH‐dependent irreversible manner. On the basis of the electrochemical findings, redox mechanistic pathways were proposed.     

On certain properties of linear iterative equations

An expression for the coefficients of a linear iterative equation in terms of the parameters of the source equation is given both for equations in standard form and for equations in reduced normal form. The operator that generates an iterative equation of a general order in reduced normal form is also obtained and some other properties of iterative equations are established. An expression for the parameters of the source equation of the transformed equation under equivalence transformations is obtained, and this gives rise to the derivation of important symmetry properties for iterative equations. The transformation mapping a given iterative equation to the canonical form is obtained in terms of the simplest determining equation, and several examples of application are discussed.     

Molybdenum(0) and Tungsten(0) Complexes with P,S and P,Se Monooxidized Bis(phosphanyl)amine Ligands

Reactions of monooxidized thioyl and selenoyl bis(phosphanyl)amine ligands C₁₀H₇‐1‐N(P(E)Ph₂)(PPh₂) [E = S ( 1 ), Se ( 2 )] with Mo(CO)₄(pip)₂ and W(CO)₄(cod) afforded the complexes [M(CO)₄{ 1 ‐κ²P,S}] [M = Mo ( 3 ), W ( 4 )] and [M(CO)₄{ 2 ‐κ²P,Se}] [M = Mo ( 5 ), W ( 6 )]. Complexes 3 – 6 were characterized by multinuclear NMR (¹H, ¹³C, ³¹P, and ⁷⁷Se NMR) and IR spectroscopy. Crystal‐structure determinations were carried out on 3 , 5 , and 6 , which represent the first examples of structurally characterized complexes of such ligands with group‐6 metal carbonyls.     

Effect of displacement on resistance and capacitance of polyaniline film

This paper investigates the properties of displacement sensors based on polyaniline (PANI) films. About 1 wt% of PANI micropowder is mixed and stirred in a solution of 90 wt% water and 10 wt% alcohol at room temperature. The films of PANI are deposited from solution by drop-casting on Ag electrodes,which are preliminary deposited on glass substrates. The thicknesses of the PANI films are in the range of 20 μm-80 μm. A displacement sensor with polyaniline film as an active material is designed and fabricated. The investigations showed that,on average,the AC resistance of the sensor decreases by 2 times and the capacitance accordingly increases by 1.6 times as the displacement changes in the range of 0 mm-0.5 mm. The polyaniline is the only active material of the displacement sensor. The resistance and capacitance of the PANI changes under the pressure of spring and elastic rubber,and this pressure is created by the downward movement of the micrometer.