Vol. 80 0.70 g. was shown by infrared analysis to be the starting alcohol IX.The main fraction from the column was then dissolved in 13 ml. of 5% methanolic potassium hydroxide and boiled under reflux for 3 hours to effect hydrolysis. The solution was Rochester, N. Y.(18) K. Folkers and F. Koniuszy (U. S. Patent 2,370,651, March 6, 1945) give for dihydro-/?-erythroidine hydrobromide, m.p, 231-231.5°, ck25d + 107.5°(in water).

No abstract

No abstract

No abstract

The second harmonic generation (SHG) coefficients dij of several corona-poled guest-host and side-chain polymers have been measured and studied over time using a new Maker Fringe analysis. The electro-optic coefficient r33 and scattering losses have also been measured in thin-film waveguides, on silicon and glass substrates, made from some of the polymers. Kleinman symmetry (d15=d31) was not valid for near-resonant SHG in these materials and d15/d31 was determined. Stable values of d33, for a fundamental of 1.064 μm, were as high as 40 pm/V for one of the side-chain polymers. Optical waveguide losses determined from scattering measurements were as low as 0.4 dB/cm at 1.06 μm.

No abstract

Several related syntheses for the preparation of 1-alkyl-and l-aryl-5-aminotetrazoles have been reported in the literature. These syntheses start with monoalkylor aryl-substituted thioureas (1-3), cyanamides (4), or nitriles (5, 6). The same compounds can be prepared from 1-alkyl-and l-aryl-2-aminoguanidines. Examination of the possible reaction mechanisms, in each of the methods, suggests that the formation and cyclization of an alkyl or aryl substituted guanyl-SUMMARY 5-Cyclohexylamino-, 5-benzylamino-, and 5-methylamino-tetrazole are formed in 2-11% yield by the cyclization of the respective guanylazides; the principal product is the isomeric l-substituted-5-aminotetrazole. 5-Methylaminotetrazole is also formed in about 0.6% yield by the reaction of hydrazoic acid and acetoni-

These data pertain to the mechanisms of uncatalyzed and catalyzed cis-trans and linkage isomerization for 11 complexes of the type (R3P)2Pd(tet)2, where R3P = CH3P(C6H5)2, (CH3)2PCeH5, (C6H5)3P, (C6H5)2PCH2-CH2P(C3H3)2 (abbreviated diphos), or (C6Hs)3-"P(CH2C6H5)" in = 1-3) and tet = 5-methyl or 5-trifluoromethyl tetrazolate. Evidence is found for the ambidentate behavior of the tetrazoles, wherein coordination of either the Ni or N2 nitrogen is observed. The complexes have been studied in solution by proton and fluorine nuclear magnetic resonance, electronic and infrared spectroscopy, and conductometric methods. The ambidentate behavior of tetrazoles and the effects of solvent, phosphine, and the nature of the anion on the solution behavior and on the isomerization mechanisms were ascertained. When the isomerizations are catalyzed by phosphines, tetrazole exchange is more rapid than phosphine exchange, whereas in the absence of excess phosphine, phosphine exchange is more rapid than tetrazole exchange. Equilibrium and activation thermodynamics were determined and profile diagrams were constructed for these processes. A unified mechanism for isomerization of square-planar complexes is developed and discussed in terms of orbital symmetry selection rules.Recent investigations have demonstrated that isomerization catalyzed by L* results in no L and L* interchange.3 This was taken to imply that any fivecoordinate intermediate or transition state cannot have a regular geometry and must be distorted in such a way that L* and L can never become equivalent. This is not inconsistent with X-ray data which suggests nonregular geometry for a five-coordinate d8 complex.9