Muonium adds to allyl chloride, CH2=CHCH2Cl, to form two radicals: MuC
H2CHCH2Cl (main product) and .CH2CHMuCH2Cl (minor product). Both radic
als were fully characterized by muSR and muLCR. In the main product, t
he LCR lines due to the Cl-35 and Cl-37 nuclei were observed. Also, th
e temperature dependence of various hyperfine coupling constants (hfc)
indicates that both Mu and Cl eclipse the unpaired electron p(z)-orbi
tal in the minimum energy conformation. For the fragment -CH2Cl, the p
resence of Mu in the beta'-position is found to affect significantly t
he hfc of Cl in the beta-position; an internal rotational barrier of 1
2 kJ mol-1 was estimated using a simple V2 torsional potential.