▁Ir O 4 + . ▁ ▁Arg on ▁m eth yl ▁c ations , ▁( or ▁m eth y li um arg on ) ▁Ar x CH 3 + ▁are ▁known ▁for ▁n = 1 ▁to ▁ 8 . ▁CH 3 + ▁is ▁a ▁Y ▁shape , ▁and ▁when ▁arg on ▁atoms ▁are ▁added ▁they ▁go ▁above ▁and ▁below ▁the ▁plane ▁of ▁the ▁Y . ▁If ▁more ▁arg on ▁atoms ▁are ▁added ▁they ▁line ▁up ▁with ▁the ▁hydro gen ▁atoms . ▁ Δ H 0 ▁for ▁Ar CH 3 + ▁is ▁ 1 1 ▁k cal / m ol , ▁and ▁for ▁Ar 2 CH 3 + ▁it ▁is ▁ 1 3 . 5   k cal / m ol ▁( for ▁ 2 Ar ▁+ ▁CH 3 + ). ▁ ▁Bor ox yl ▁ring ▁c ation ic ▁complex es ▁with ▁arg on ▁[ Ar B 3 O 4 ]+ , ▁[ Ar B 3 O 5 ]+ , ▁[ Ar B 4 O 6 ]+ ▁and ▁[ Ar B 5 O 7 ]+ ▁were ▁prepared ▁via ▁a ▁las er ▁v apor ization ▁at ▁cry ogen ic ▁temper atures ▁and ▁investig ated ▁by ▁inf ra red ▁gas ▁phase ▁spect ro sc opy . ▁They ▁were ▁the ▁first ▁large ▁stable ▁gas ▁phase ▁complex es ▁that ▁feature ▁strong ▁d ative ▁bond ing ▁between ▁arg on ▁and ▁bor on . ▁ ▁Dic ations ▁ ▁Dic ations ▁with ▁arg on ▁are ▁known ▁for ▁the ▁coin age ▁met als . ▁Kn own ▁dic ations ▁include ▁Cu Ar n