Direct determination of absolute configuration of monoalcohols by bis(magnesium porphyrin)

Ethane bridged bis(Mg porphyrin) has been found to be an effective sensor for the direct determination of the absolute configuration of a variety of monoalcohols at millimolar concentrations and room temperature based on the CD exciton chirality method. Examination of a variety of synthetic and natural monoalcohols, including alpha-substituted aliphatic and aromatic alkanols with one chiral center, as well as alicyclic alcohols with 2-5 chiral centers, gave consistent results. In the case of alcohols with multiple chiral centers, the absolute configuration of the carbon alpha to OH is always read out.     

Ion-molecule reactions of 2-methoxyethanol with some amines, carboxylic acids and amino acids under chemical ionization conditions

2-Methoxyethanol chemical ionization of amines, carboxylic acids and amino acids has been found to produce numerous adduct ions. The most intense adduct ions for amines are [M + H](+) and [M + 77](+), for carboxylic acids [M + 27](+), [M + 59](+) and [M + 77](+), and for amino acids [M + H](+), [M + 13](+), [M + 27](+) and [M + 77](+). Either the adduct ion [M + H](+) or [M + 77](+) was the most abundant ion found for amino acids. The proton affinities of amino acids are noticed to control the formation of the [M + H](+) and [M + 77](+) ions. The relative abundance of [M + 13](+) and [M + 27](+) ions varied for different amino acids being most intense for phenylalanine and aspartic acid. Copyright 1999 John Wiley & Sons, Ltd.     

Status of electroweak phase transition and baryogenesis

I review recent progress on the electroweak phase transition and baryogenesis, focusing on the minimal supersymmetric Standard Model as the source of new physics.     

Synthesis of Zn-, Mn-, and Fe-Containing Mono- and Heterometallated Ethanediyl-Bridged Porphyrin Dimers

New ethanediyl-bridged unsymmetrical mono- and heterometallated dimers of 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrin (H₂oep) containing transition-metal ions (Mn and Fe) were synthesized by a facile stepwise metallation/demetallation process under mild conditions. The novel metallation strategy initially involved the predominant insertion of Zn into one of the two porphyrin rings of the free-base dimer, followed by the incorporation of Mn or Fe into the other porphyrin ring under exceptionally mild conditions, giving corresponding heterometallic dimers; the subsequent removal of Zn yielded mono-transition-metal dimers. The emission spectrum of the monozinc dimer predominantly exhibited fluorescence bands of the free-base porphyrin component, indicating a very efficient energy-transfer process. Conversely, emission of the free-base or Zn porphyrin component of transition metal containing dimers was strongly quenched due to photoinduced electron transfer.     

Direct determination of absolute configuration of carboxylic acids by cyclooctapyrrole

Octaphyrin O1 has been found to be an effective sensor for the direct determination of absolute configuration of a variety of carboxylic acids at mM concentrations at room temperature based on CD exciton chirality method.     

连续波锁模P_r~（3＋）：YLF激光器

本文报导了采用氩离子激光器来泵浦Ｒｒ￣（３＋）：ＹＬＦ晶体，应用声光调制器实现了主动锁模；同时应用振动─高反射平面镜也实现了被动锁模，两种锁模均得到了ｐｓ光脉冲。据作者了解这是这种晶体材料的第一次锁模运转。