lithium triethylborohydride in tetrahydrofuran treating 1 mmol of the complex in THF at -80°C with a 1 M THF soln. of LiB(C2H5)3H; storing for 4h; evaporation to dryness under reducedpressure;; extraction with toluene; pptn. by addn. of methanol; detn. by 31P NMR in CD3C6D5;;