Coinage metal complexes of multidentate Pacman phosphane ligands.

We present the extension of Pacman ligands to bidentate phosphane ligands enabling them to bind metals in their sterically protected cavity. The coordination of coinage metals shows the ability of the ligand to adopt different coordination modes by distortion, of which some additionally include the imine nitrogen atoms. Besides the coordinated metal, the substitution on the phosphorus atoms influences the type of coordination.

On the Dynamic Behavior of Pacman Phosphanes─A Case of Cooperativity and Redox Isomerism.

In solution, the Pacman chlorophosphane (2Cl) shows fast exchange of the endo/exo-orientation of the two P-Cl bonds in the molecule featuring cooperativity. Experimental and quantum mechanical investigations of the inversion on the phosphorus(III) centers reveal a crucial role of chloride ions in the dynamic process. To confirm the results, the homologous Pacman halogen-phosphanes 2X were prepared by halogen exchange reactions (X = F, Br, and I). Besides accelerated dynamic behavior for the heavier analogues, significant differences in the molecular structure are caused by the halogen exchange reactions, including the formation of an endo-endo substituted Pacman fluorophosphane as well as dicationic species by phosphorus halogen bond dissociation. The latter process can be regarded as redox isomerism since two PIII atoms in 2X become PV centers in the dications.

Learning of a golf putting task with varying contextual interference levels induced by feedback schedule in novices and experts.

Switching between tasks during practice can affect motor learning. This study tested whether switching feedback content has any effects on learning to perform golf putts without full visibility. 60 participants (44 men, 16 women; M age = 26.3 yr., SD = 6.6) practiced golf putts without seeing the ball movement. 30 of the participants were golfers with moderate expertise, and 30 were novices. They received feedback regarding their putts, either on the angle or on the distance in one of three feedback schedules: blocked, serial-blocked, or serial. Independent of the expertise level, learning was not affected by the feedback schedule. The strong linkage between the two components--direction and distance--may have prevented a sufficient level of contextual interference.