Pentavalent P Compound Having The Structure (x=c*)-p(=x) Or (cyano*)-p(=x) Where X Is Chalcogen, * Indicates A Direct Bond Of The C Of The C=x Group Or Of The C Of The Cyano Group Directly To The P Atom, And The Other Atoms Bonded Directly To The P Atom Are Either Carbon And Hydrogen (9/53a9; 9/53p; 9/53y) Patents (Class 987/120)