Crystal structures of phosphine-supported (η5-cyclo-penta-dien-yl)molybdenum(II) propionyl complexes.

Three cyclo-penta-dienylmolybdenum(II) propionyl complexes featuring tri-aryl-phosphine ligands with different para substituents, namely, dicarbon-yl(η5-cyclo-penta-dien-yl)propion-yl(tri-phenyl-phosphane-κP)molybdenum(II), [Mo(C5H5)(C3H5O)(C18H15P)(CO)2], (1), dicarbon-yl(η5-cyclo-penta-dien-yl)propion-yl[tris-(4-fluoro-phen-yl)phosphane-κP]molybdenum(II), [Mo(C5H5)(C3H5O)(C18H12F3P)(CO)2], (2), and dicarbon-yl(η5-cyclo-penta-dien-yl)propion-yl[tris-(4-meth-oxy-phen-yl)phosphane-κP]molybdenum(II) dichloromethane solvate, [Mo(C5H5)(C3H5O)(C21H21O3P)(CO)2]·CH2Cl2, (3), have been prepared from the corresponding ethyl complexes via phosphine-induced migratory insertion. These complexes exhibit four-legged piano-stool geom-etries with mol-ecular structures quite similar to each other and to related acetyl complexes. The extended structures of the three complexes differ somewhat, with the para substituent of the tri-aryl-phosphine of (2) (fluoro) or (3) (meth-oxy) engaging in non-classical C-H⋯F or C-H⋯O hydrogen-bonding inter-actions. The structure of (3) exhibits modest disorder in the position of one Cl atom of the di-chloro-methane solvent, which was modeled with two sites showing approximately equivalent occupancies [0.532 (15) and 0.478 (15)].

Molecular Weight Dependence of Block Copolymer Micelle Fragmentation Kinetics.

The effect of molecular weight (M) on the fragmentation kinetics of micelles formed by 1,2-polybutadiene-block-poly(ethylene oxide) (PB-PEO) copolymers was studied in the ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide. A series of six samples, with total M ranging from 104 to 105 g mol-1 and nearly constant composition (fPEO ≈ 0.4), were examined; all six formed spherical micelles with PEO coronas. Nonequilibrium PB-PEO micelles were prepared by direct dissolution, a process that systematically produces nanoparticles with mean aggregation numbers more than twice the equilibrium values. When subjected to high temperature annealing (170 °C), the average micelle radius was found to decrease substantially, as determined by temperature-jump dynamic light scattering (T-jump DLS) and time-resolved small-angle X-ray scattering (TR-SAXS). The characteristic fragmentation times (τ) were found to increase strongly with increasing degree of polymerization N, as τ ∼ N1.8. This result compares favorably with the prediction of a previously untested model.

Postgraduate Experiences With an Advanced Reproductive Health and Abortion Training and Leadership Program.

BACKGROUND AND OBJECTIVES: Family physicians are critical to reproductive health service provision including miscarriage management and abortion care, but many graduates report barriers in integrating these services into practice. We designed and implemented CREATE (Continuing Reproductive Education for Advanced Training Efficacy), an elective advanced training and leadership program for senior residents aimed to help new graduates integrate miscarriage and abortion care into practice. METHODS: We surveyed all 53 program graduates at graduation, and 47 completed a follow-up survey in March 2016. We describe program graduates' current reproductive health practices and differences by respondent characteristics. We report facilitators (or enabling factors) and barriers that graduates encountered in attempting to integrate reproductive health care into practice, as well as the perceived impact of the CREATE program. RESULTS: Forty-two percent of CREATE graduates were providing miscarriage management and 35% were providing abortion care at the time of the follow-up survey. Factors associated with abortion provision at follow-up include strength of intention to provide at graduation and higher volume of uterine aspirations performed during residency. Graduates reported a range of barriers, including internal factors such as strength of competing interests, and external barriers such as administrative and staff resistance. Graduates found the additional procedural training, networking opportunities, and the complication simulation to be the most helpful aspects of the CREATE program. CONCLUSIONS: The CREATE program model may provide a useful template for family medicine residencies working to incorporate advanced abortion training or other advanced procedural skills into their curricula. Future curricular interventions should consider providing additional postgraduate support, particularly in provider shortage areas.