By Protic Reagents

methanol, hydrogen bromide, and hydrogen iodide cleave the Te—M bond heterolytically with the bonding electon pair remaining with the tellurium atom . 

---

The rhenium analog behaves similarly, being cleaved quickly by protic reagents in the presence of pyridine, although inert in its absence (7). 

All of the (C8H8)2An complexes are exceedingly sensitive to oxygen. Metal-ring bonding appears to be more ionic in thoracene than uranocene. (C8H8)2Th is rapidly destroyed by protic reagents, whereas uranocene is hydrolyzed only slowly. 

The >C = P- and -N = P- bonds, being polar, are attacked by protic reagents resulting in 1,2-addition, the proton being bonded to carbon or nitrogen. 

---