NaSn(CO)F and NaSnCOF·HO: two tin(II) fluoride oxalates display large birefringence.

Birefringent materials play an important role in laser techniques as an essential part of optical devices. Therefore, the exploration of high-performance birefringent materials has been a central focus of researchers. Herein, two tin(II) fluoride oxalates NaSn(CO)F and NaSnCOF·HO were gained by the combination of birefringence-active groups of Sn with stereochemically active lone pairs and planar π-conjugated [CO] groups.

Adaptive designs for sequential experiments.

Various adaptive designs have been proposed and applied to clinical trials, bioassay, psychophysics, etc. Adaptive designs are also useful in high cost engineering trials. More and more people have been paying attention to these design methods.