trimethylstannyl chloride in carbon disulfide under N2, reaction of P4 with Br2 in CS2, followed by treatment with C(CH3)3SnCl; further products: PBr3, PClBr2, PCl2Br, PCl3, P7Br3, P4Br2, and P4BrCl; not isolated, identified by 31P-NMR spectroscopy;