▁The ▁parent ▁member ▁B H 3 ▁is ▁called ▁bor ane , ▁but ▁it ▁is ▁known ▁only ▁in ▁the ▁g ase ous ▁state , ▁and ▁dim er ises ▁to ▁form ▁di bor ane , ▁B 2 H 6 . ▁The ▁larger ▁bor anes ▁all ▁consist ▁of ▁bor on ▁clusters ▁that ▁are ▁poly hed ral , ▁some ▁of ▁which ▁exist ▁as ▁is om ers . ▁For ▁example , ▁is om ers ▁of ▁B 2 0 H 2 6 ▁are ▁based ▁on ▁the ▁fusion ▁of ▁two ▁ 1 0 - atom ▁clusters . ▁ ▁The ▁most ▁important ▁bor anes ▁are ▁di bor ane ▁B 2 H 6 ▁and ▁two ▁of ▁its ▁py ro ly s is ▁products , ▁pent abor ane ▁B 5 H 9 ▁and ▁dec abor ane ▁B 1 0 H 1 4 . ▁A ▁large ▁number ▁of ▁an ionic ▁bor on ▁hyd rides ▁are ▁known , ▁e . g . ▁[ B 1 2 H 1 2 ] 2 − . ▁ ▁The ▁formal ▁ox id ation ▁number ▁in ▁bor anes ▁is ▁positive , ▁and ▁is ▁based ▁on ▁the ▁assumption ▁that ▁hydro gen ▁is ▁counted ▁as ▁− 1 ▁as ▁in ▁active ▁metal ▁hyd rides . ▁The ▁mean ▁ox id ation ▁number ▁for ▁the ▁bor ons ▁is ▁then ▁simply ▁the ▁ratio ▁of ▁hydro gen ▁to ▁bor on ▁in ▁the ▁mole c ule . ▁For ▁example , ▁in ▁di bor ane ▁B 2 H 6 , ▁the ▁bor on ▁ox id ation ▁state ▁is ▁+ 3 , ▁but ▁in ▁dec abor ane ▁B 1 0