Synthesis, X‐Ray Structure and Complexation Behavior of the New Tripodal Phosphane Ligand cis, cis ‐1,3,5‐Tris[(diphenylphosphanyl)methyl]1‐1,3,5‐trimethylcyclohexane (tdppmtmcy). Crystal Structure of Ir(tdppmtmcy)(CO)Cl

The introduction of three methyl groups into the ipso positions of the cyclohexane ring in cis,cis ‐1,3,5‐tris[diphenylphosphanyl)methyl]cyclohexane (tdppmcy) ( 1 ) leads to the new tripodal phosphane ligand cis,cis ‐1,3,5‐tris(diphenylphosphanyl)methyl]1‐1,3,5‐trimethylcyclohexane (tdppmtmcy) ( 5 ). The dynamic behavior is studied by variable‐temperature NMR spectroscopy and compared with the structure (X‐ray analysis) in the solid state. Treatment of 5 with Ir(PPh 3 ) 2 (CO)Cl gives 6 where the two PPh 3 groups are replaced by two (diphenylphosphanyl)methyl groups of the ligand 5 . In addition, an intramolecular CH metalation takes place resulting in the oxidative addition of a ring methylene CH bond to the metal. The X‐ray structure of 6 is determined.