An Unknown Coordination Mode of the Phosphite Unit and a Carbon-Free Heterocycle in Two Different Heterobimetallic Alumophosphites

The unique alumophosphite reagent LAl(SH)(μ-O)P(OEt)₂ was prepared and used for the synthesis of the heterobimetallic alumophosphites [{κ²-S,P-LAl(S)(μ-O)P(OEt)₂}₂Zn] and [{κ⁴-S,O,O-LAl(SLi)(μ-O)P(OEt)₂}₂]. The first contains a rare example of two carbon-free five-membered heterocycles (Al−S−Zn−P−O) connected in a spiro fashion through the zinc atom, whereas the second possesses an unknown example of a coordination environment of a phosphite unit M−O−P(μ-OEt)₂M with an uncoordinated lone electron pair on the phosphorus center.