Setting boundary condition in PDE,

I would like to solve the following PDEs:

where and are dimensionless concentrations, T and X are respectively dimensionless time and space.

The initial values (T = 0) are:

The boundary condition that I am not able to set using the PDEPE solver of Matlab are:

at ,

at ,

How do I write the code, to solve these PDEs? In particular I have troubles to define the second BC at .