An asymmetric iodolactonization reaction catalyzed by a zinc bis-proline–phenol complex

The intramolecular zinc bis-proline-phenol complex 2a was found to promote enantioselective iodolactonization reactions of both electron-rich and electron-poor 5-aryl-5-hexenoic acids affording δ-iodolactones in good chemical yields with up to 82% enantiomeric excess. The reactions were found to be insensitive to air and moisture, providing an experimentally simple protocol for synthetically useful compounds.     

A method for analysing nesting techniques for the linearized shallow water equations

A method for analysing different nesting techniques for the linearized shallow water equations is presented. The problem is formulated as an eigenvector–eigenvalue problem. A necessary condition for stability is that the spectral radius of the propagation matrix is less than or equal to one. Two test cases are presented. The first test case is analysed, and effects of enforcing volume conservation and nudging in time are studied. A nesting technique is found that causes no growth of any eigenvectors for reasonable time steps. This nesting technique is then used on both test cases, and results are compared to an everywhere refined model and a coarse grid model. Copyright © 2002 John Wiley & Sons, Ltd.     

Estimates of ‖e itf‖ A(Γ), when Γ ⊂ ℝ n is a curve andf is a real-valued functionis a curve andf is a real-valued function

It is shown that there exists ann×n matrix all of whose eigenvalues and off-diagonal elements are prescribed. The number of such matrices is finite.     

Characteristics of the consistent ground state of the random phase approximation

Detailed considerations of the ground-state vector derived for the random phase approximation obtained earlier in a generator coordinate representation employing the unitary group parameter space reveal a particular correlated pair structure. The results of explicit calculations of ground-state averages are discussed.     

UV and IR absorption cross-sections of HCHO, HCDO, and DCDO

UV (240-370 nm) and IR (3200-1500 cm(-1)) absorption cross-sections of HCHO, HCDO, and DCDO in a bath gas of N(2) at atmospheric pressure and 296 K are reported from simultaneous measurements in the two spectral regions. Cross-sections were placed on an absolute scale through quantitative conversion of formaldehyde to CO and HCOOH by titration with Br atoms, also monitored by FTIR. The integrated UV absorption cross-sections of HCHO, HCDO, and DCDO are equal to within the experimental uncertainty.     

Electron propagator theory and application

Summary The electron propagator theory is presented with somewhat of a historical perspective and the working equations are developed with the aim of taking advantage of molecular point group symmetry. A new electron propagator code, the vectorized electron propagator program (VEP), is introduced without full details about its structure and capabilities (such details are being published elsewhere). Applications to the (UV) photoelectron spectra of some donor-acceptor complexes of borane with carbon monoxide and water are presented at the level of second-order theory as an illustration of the theory and the VEP code.