Bridgehead imine substituted cyclopentadithiophene structural units offer the opportunity to modify the electronic properties, in particular, the HOMO–LUMO energy levels of donor–acceptor polymers with unprecedented precision. Utilizing a common synthetic pathway, copolymers with high average molecular weights, a variety of functionality, and properties suitable for solar cell incorporation can be generated. The fabrication of organic photovoltaic devices with these new materials is demonstrated.

13 C NMR spectroscopy is used to characterize the microstructure of polypropylene (PP) obtained using a nickel α-keto-β-diimine initiator activated with methylaluminoxane (MAO) at different reaction temperatures (T rxn ). The product prepared at −20 °C has structural features that resemble an ethylene-propylene copolymer. We find that the main sequences present in this sample arise as a result of normal 1,2-insertion and that propylene sequences are predominantly isotactic (m = 88%, mmmm = 63%). There is also evidence of ethylene-like sequences as a result of 3,1-enchainment, and from 2,1-insertion. A reduction in T rxn to −60 °C results in a polymer that has undetectable regioirregularities and is highly isotactic (m = 93%, mmmm = 85%). Moreover, the application of stereo propagation models gives indication that the isospecificity is a result of enantiomorphic site control.

Complex considerations: The synthesis and characterization of a discrete cationic nickel–methallyl complex (see structure: Ni green, N blue, O red) provided insight into the propagating sites generated by using α‐keto‐β‐diimine–nickel olefin‐polymerization catalysts. The addition of Al(C6F5)3 led to carbonyl coordination to aluminum, further depletion of the electron density at the nickel center, and a substantial increase in reactivity towards ethylene.

Background: Assessment of an individual medical school’s performance in the match is an important outcome of the educational program. Unfortunately, student rank lists are not public. A method to objectively gauge the quality of an institution’s match regardless of student preference has not been described in the literature.Objective: This manuscript serves to determine the relative weights of included variables and derive a statistically valid Match Quality Score (MQS).Design: Between 2016 and 2018, student affairs experts derived from a national cohort validated the MQS by scoring factitious mini-match lists that covered three variables: student’s Match Status, specialty Competitiveness, and residency program Reputation.Results: Of the variables assessed, only Match Status and Competitiveness were found to be significant. We derived the resulting coefficients for the Match Quality Score (MQS) as: [3.74A (# students successfully matched) + 2.34B (# students matching into their initial specialty in the SOAP process) + 1.77C (# students who secured a SOAP position in another specialty) + 0.26D (# students matching into a specialty where there are more applicants than spots)]/Total # students.Conclusions: The MQS is a potentially useful educational outcome measurement for US medical schools and may be considered as an outcome measure for continuous quality improvement to tailor future institutional changes to training, mentoring, and student-advising programs.

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