A divergent synthetic strategy allowed access to several members of a new class of helicenes, the "expanded helicenes", which are composed of alternating linearly and angularly fused rings. The strategy is based on a three-fold, partially intermolecular [2+2+n] (n = 1 or 2) cycloaddition with substrates containing three diyne units. Investigation of aggregation behavior, both in solution and in the solid state, revealed that one of these compounds forms an unusual homochiral, π-stacked dimer via an equilibrium that is slow on the NMR time scale. The versatility of the method was harnessed to access a selenophene-annulated expanded helicene that, in contrast to its benzannulated analogue, exhibits long-range π-stacking in the solid state. The new helicenes possess low racemization barriers, as demonstrated by dynamic H NMR spectroscopy.

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The [BP 3 i P r ]Co(I) synthon Na-(THF) 6 {[BP 3 iPr ]CoI} (1, [BP 3 iPr ] = κ 3 -PhB(CH 2 P i Pr 2 ) 3 − ) reacts with PhSiH 3 or SiH 4 to form unusual {[BP 2 iPr ] -(SiH 2 R)CoH 2 }Si{H 2 Co[BP 3 iPr

Spray-dried encapsulated milkfat powders were prepared from stable emulsions containing 40-60% milkfat and carbohydrate matrices. Moisture content of the spray-dried powders varied from 14%. Lowest free fat content (< 10%) was found in powders with 40% fat, encapsulated in sucrose. Angles of repose ranged from 37 to 46", and correlated with powder flow (p = 0.01). Bulk density was dependent on the encapsulant and declined with increasing fat content. Product density did not influence powder recovery through the cyclone of the dryer. Particle size distribution ranged from 20 to 120 ym with 80% of the particles < 100 pm. Powders with best physical properties were made with 40-50% butteroil encapsulated in sucrose.

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Divalent complexes of vanadium were synthesized employing bulky silyl(aryl)amido ligands −N(Si i Pr 3 )DIPP and −N(Si t Bu 2 Me)DIPP (DIPP = 2,6-i Pr 2 C 6 H 3 ). Solid-state structural characterization revealed that although the ligand −N-(Si i Pr 3 )DIPP supports a monomeric, bis(amido) complex of vanadium, its constitutional isomer −N(Si t Bu 2 Me)DIPP affords a homoleptic complex in which the vanadium center is sandwiched between the arene rings, an unusual binding mode for arylamido ligands. Magnetometry studies indicate that V[N(Si i Pr 3 )DIPP] 2 and V[(η 5 -DIPP)N(Si t Bu 2 Me)] 2 have similar high-spin d 3 electron configurations. However, spectroscopic methods, including electron paramagnetic resonance, nuclear magnetic resonance, infrared, and UV−visible spectroscopies, in addition to cyclic voltammetry and reactivity studies, suggest that V[N(Si i Pr 3 )DIPP] 2 is stereochemically nonrigid in solution, while V[(η 5 -DIPP)N(Si t Bu 2 Me)] 2 is not. This nonrigidity explicitly impacts the reactivity of V[N(Si i Pr 3 )DIPP] 2 , which can be used to access both amido-bound and arene-bound complexes. Moreover, treatment of V[N(Si i Pr 3 )DIPP] 2 with single and multielectron oxidants reveals a range of transformations including an intramolecular sp 3 C−H bond activation.

Two new base-free hydrosilylene complexes of iron were synthesized using the novel starting material Cp*( PrMeP)FeMes. These Cp*( PrMeP)Fe(H)SiHR (R = DMP, Trip) complexes are in equilibrium with the corresponding iron silyl complexes, Cp*( PrMeP)FeSiHR, which can be trapped and characterized for R = Trip. Unlike the Ru analogues, the Fe silylene complex with R = DMP is observed to undergo an intramolecular C-H activation involving formal addition of a benzylic C-H bond across the Fe-Si bond. This increased activity for bond activations is also observed for reactions with hydrogen, where Fe reacts faster than a Ru analog to form the hydrogenation product, Cp*( PrMeP)HFeSiHDMP.

This study has demonstrated that the analysis stage of QLF is reliable between examiners and within multiple attempts by the same examiner, when analysing in vitro lesions. Novices at the technique should be trained before analysing experimental data.