A Nontrigonal Tricoordinate Phosphorus Ligand Exhibiting Reversible "Nonspectator" L/X-Switching.

We report here a "nonspectator" behavior for an unsupported L-function σ -P ligand (i.e. P{N[o-NMe-C H ] }, 1a) in complex with the cyclopentadienyliron dicarbonyl cation (Fp ).

Precursor reaction kinetics control compositional grading and size of CdSe S nanocrystal heterostructures.

We report a method to control the composition and microstructure of CdSe S nanocrystals by the simultaneous injection of sulfide and selenide precursors into a solution of cadmium oleate and oleic acid at 240 °C. Pairs of substituted thio- and selenoureas were selected from a library of compounds with conversion reaction reactivity exponents ( ) spanning 1.3 × 10 s to 2.

A Library of Selenourea Precursors to PbSe Nanocrystals with Size Distributions near the Homogeneous Limit.

We report a tunable library of N,N,N'-trisubstituted selenourea precursors and their reaction with lead oleate at 60-150 °C to form carboxylate-terminated PbSe nanocrystals in quantitative yields. Single exponential conversion kinetics can be tailored over 4 orders of magnitude by adjusting the selenourea structure. The wide range of conversion reactivity allows the extent of nucleation ([nanocrystal] = 4.

Psychometric Properties of the Classroom Assessment Scoring System (Pre-K): Implications for Measuring Interaction Quality in Diverse Early Childhood Settings.

The Classroom Assessment Scoring System (CLASS) is an observational instrument assessing the nature of everyday interactions in educational settings. The instrument has strong theoretical groundings; however, prior empirical validation of the CLASS has exposed some psychometric weaknesses. Further the instrument has not been the subject of psychometric analysis at the indicator level.

NANOMATERIALS. A tunable library of substituted thiourea precursors to metal sulfide nanocrystals.

Controlling the size of colloidal nanocrystals is essential to optimizing their performance in optoelectronic devices, catalysis, and imaging applications. Traditional synthetic methods control size by terminating the growth, an approach that limits the reaction yield and causes batch-to-batch variability. Herein we report a library of thioureas whose substitution pattern tunes their conversion reactivity over more than five orders of magnitude and demonstrate that faster thiourea conversion kinetics increases the extent of crystal nucleation.