Mass spectra of diborane-d6 and ethane-d6

The comple te mass spectra of B2D6 and C2D6 and t he partial spectrum of B2DSH h ave been obtained for ioni zin g voltages of 50 volts and 70 volts.An analytical procedure is given for deriving the contribu tion of all ions containing a hydrogen atom from the polyisotopic spectrum of a m ixture of B2D6 and B2DsH .A comparison of spectra of B2D6 and B2H6 and of C2D6 an d C2H6 indi cates that substitution of deuterium for hydrogen has only a sli gh t effect on t he di ssociation probabilities in dibor ane and ethane.An excep tion is t he occurren ce of a metastable t ran it ion in B2D6 that does not occur in B2Hij viz B2DS+ ...... B2D3++ 2D .S im ple statistical consid erations, based upon the assumption of equal probabi lities for t he removal of a deuterium or a protium , g ive a di ssociatio ll pattern that differs by more t han experimental error fr om th at observed .