Computer checking of rotational line intensity factors for diatomic transitions

Previously published analytical formulae for the rotational line intensity factors of diatomic molecules have been compared with results from a comprehensive computer program, which determines numerical intensity factors for both spin-allowed and spin-forbidden electric and magnetic dipole transitions in diatomic molecules. The comparison uncovered several typographical errors and a few algebraic errors in the published formulae. The changes required in the formulae to give agreement with the results from the computer program are tabulated.     

Penicillin N-cyanosulphilmines; cyanamide/iodobenzene diacetate,a convenient cyanonitrene reagent for N-cyano sulphilmines,sulphoximines, phosphinimines and aziridines

Cyanamide with iodobenzene diacetate give cyanonitrene adducts of sulphides, sulphoxides, phosphines, and olefins. Penicillins give $\text{N}$-cyanosulphilimines, shown by intramolecular N-H...N hydrogen bonding or NMR ASIS to have β(S) stereochemistry.     

Leptoproduction and Drell-Yan processes beyond the leading approximation in chromodynamics

The problem of going beyond the leading logarithmic approximation in QCD for leptoproduction and Drell-Yan processes is considered. All the coefficient functions for leptoproduction are evaluated to order α_sQ²) (apart from two-loop corrections to logarithmic exponents). Existing calculations are thus completed and in part corrected. Particular attention is given to the constraint imposed by the validity at all Q² of the Adler sum rule. The question of a convenient definition of effective parton densities appropriate at this level of accuracy is discussed. Phenomenological consequences for leptoproduction are considered with special emphasis on the problem of extraction from the data of the small sea densities which are particularly sensitive to the corrections. The modifications of the Drell-Yan formula relevant for proton-nucleus processes are also explictly calculated to order α_s(Q²).     

Fiber-coupled displacement interferometry without periodic nonlinearity

Displacement interferometry is widely used for accurately characterizing nanometer and subnanometer displacements in many applications. In many modern systems, fiber delivery is desired to limit optical alignment and remove heat sources from the system, but fiber delivery can exacerbate common interferometric measurement problems, such as periodic nonlinearity, and account for fiber-induced drift. In this Letter, we describe a novel, general Joo-type interferometer that inherently has an optical reference after any fiber delivery that eliminates fiber-induced drift. This interferometer demonstrated no detectable periodic nonlinearity in both free-space and fiber-delivered variants.     

Naphthalene and anthracene cobaltates(1-): useful storable sources of an atomic cobalt anion

Reductions of CoBr(2) or cobaltocene by 3 equiv of potassium anthracene radical anion in tetrahydrofuran (THF) afford 60-80% yields of bis(anthracene)cobaltate(1-) (1), of interest as a readily accessible and quite labile source of spin-paired atomic Co(-). Although the unsolvated potassium salt of 1 is thermally unstable at 20 °C, the [K(18-crown-6)(THF)(2)](+) salt of 1 functions as a useful storable crystalline reagent for Co(-) in several reactions. Previously known classic cobaltates, [CoL(4)](-), for L = 1/2 (1,3-butadiene) (2), PF(3) (3), and P(OiPr)(3) (5), were obtained directly from 1 and structurally characterized for the first time. Anion 3 is noteworthy because it appears to possess the shortest known Co-P distance, av = 2.012(4) ?. Although the naphthalene analogue of 1 is not yet available as a pure substance, low-temperature reductions of CoBr(2) or cobaltocene by naphthalene radical anion in the presence of 1,5-cyclooctadiene (COD) afford variable yields (80-90% from CoCp(2)) of (naphthalene)(COD)cobaltate(1-) (10). Ready displacement of naphthalene in 10 by L = 1,3-butadiene, 2,2'-bipyridine, and COD occurs to give good yields of the respective [Co(L)(COD)](-), all of which have been structurally characterized. Both ligands in 10 are displaced by tert-butylisocyanide to afford [Co(CNtBu)(4)](-) (16), the first isolable and structurally characterized homoleptic alkylisocyanometalate. The molecular structure of 16 shows unprecedented bending of the isocyanides, av C-N-C = 137(2)°, for homoleptic isocyanide complexes.