Hi,
Its called (someone correct me if I'm wrong):
Dihydride-tetrakis(triphenylphosphine)ruthenium(II)
or: dihydrido-tetrakis(triphenylphosphine)ruthenium(II)
(someone correct me if I'm wrong)
It is used for the migratory insertion of hydride (H-) - reduction - and may be used to reduce alkenes to alkanes for example. I think I used or made it in the inorganic laboratory at university last year and could check my notes if you really need me to. I think it has to be made in the lab, but I could be wrong.