Highly planar amphiphilic porphyrins

A first synthesis of an asymmetric and amphiphilic β-substituted porphyrin is reported. The porphyrin can be integrated into various types of nanostructures with the amphiphilic characters in hydrophilic solvents. The one-dimensional integration may induce a magnetic interaction between the central metals.     

Coexistence of α-clustering and shell structure in40Ca

The energy spectrum and α-spectroscopic factors of⁴⁰Ca are calculated by using an α+³⁶Ar orthogonality condition model. Overall agreement is obtained with the experimental data. The model successfully produces the parity-doubletK ^π=O ⁺ and O^? α+³⁶Ar cluster bands. It is shown that the coexistence and interference of α-cluster states and shell-model states are indispensable to understand the structure of⁴⁰Ca.     

Frequency stabilization of a HeNe laser using a thin film heater coated on the laser tube

The cavity length of an internal-mirror HeNe laser was controlled using a thin film heater coated on the tube. The response speed was about ten times higher than that of the usual tube wound with a ribbon heater. The high response speed brought two merits in frequency stabilization of the laser; one was improvement of stability in the short time region and the other was the realization of a thermal modulation method, by which the cavity was stabilized at Lamb's dip.     

A 200 mJ unstable resonator Nd:YAG oscillator

We have designed and operated a positive branch 6.3 mm diameter rod Nd:YAG unstable resonator oscillator with a 12 nsec, 200 mJ Q-switched output at 10 Hz repetition rate. When followed by a single 9 mm diameter Nd:YAG amplifier output energies up to 750 mJ were obtained with a divergence less than 0.5 mrad.     

Stability constants of 2-mercaptohistamine metal complexes

Summary Stability constants of 2-mercaptohistamine (2-MH) with a number of transition metal ions were determined by a potentiometric titration method and the coordination mode of (2-MH) metal complexes were thereby characterized. With Mn^II, Fe^ll, Co^II, and Ni^II, coordination occurred through both the imidazole-nitrogen and amino groups, while with Zn^II, Cd^II, Pb^II, and Hg^II, both thiolate and amino groups, contribute to the coordination. in the 2-MH copper complex, polymer formation is suggested on the basis of visible absorption and e.p.r. spectra.     

The Reaction of Singlet Oxygen with 1,3-Dimethylindole in the Presence of Aldehydes. Formation of 1,2,4-Trioxanes

The dye-sensitized photo-oxygenation of 1,3-dimethylindole in the presence of aldehydes initially generates a zwitterionic peroxide which condenses with the carbonyl function to give the corresponding cis-fused 1,2,4-trioxanes. Acetaldehyde gives a pair of diastereomers, one of whose structures was determined by X-ray analysis (cis,cisisomer), whereas pivaladehyde gives only the cis,cis diastereomer.