Dear. researchgate members

I wanna to ask you guys who majored organic chemistry. I have read few papers about tripodal carbene complexes (as called hemicage structure). I only have seen tert-butyl substituted tripodal carbene ligand complexes with Fe, Co, Tl, Ir etc..I am wondering that is is possible to replace the tert-butyl to phenyl moiety? Also, do you guys think that is it possible to synthesize organometallic complex with d8 metal? (for example Ir) I never find this kind of structures. I really wanna know whether it is possible or not. I just only found  phenyl-phyrinde ligand based tripodal Ir complex, which is reported by Prof. Eli Zysman-Colman. I have attached example figure for carbene tripodal ligand and phenyl-pyridine tripodal Ir complex. I really need you guys comment on this question. Please understand me i didn't majored organic chemistry so my knowledge is very poor. 

Best regards

Sunwoo Kang