Which is more stable out of the given carbocation?


> 
> Which is more stable?
> 
> 
> 1. $\ce{^+C(CH3)3}$
> 2. $\ce{^+C(CD3)3}$
> 
> 
> 


I have read in Solomon's and Fryhle that the +I effect of D is more than that of H but here in this problem it is given that $\ce{(CH3)3C+}$ is more stable.


How is this possible? Since, deuterium enriches the electron density over the central carbon resulting in the diminishing of a positive charge eventually making the second structure more stable.


Second explanation can be on the basis of hyperconjugation which says that $\ce{-CH3}$ is better in showing hyperconjugation than $\ce{-CD3}$, but why is this so?




$\ce{C-D}$ bonds are stronger. Hyperconjugation is thus more easily seen with hydrogen rather than deuterium.  
 **Hyperconjugation> Inductive effects** at stabilization.I believe you can reason the rest out by yourself.   
 To see why $\ce{C-D}$ bonds are stronger. 
  

[See this](https://chemistry.stackexchange.com/questions/70128/why-is-a-c-d-bond-stronger-than-a-c-h-bond) 


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