# Coupling constant in 1H NMR with phosphorus

I had a doublet with peaks at 5.6336 and 5.5886 ppm with the machine running at 300 MHz, I got a $J_P$$_H$ of 13.5 Hz is this correct for this molecule ( Ethoxycarbonylmethyl(triphenyl)phosphonium Bromide) This value is larger than the hydrogen coupling constants for the C-C bonds, is this larger coupling constant a consequence of the phosphorous?