curve fitting to data set

Hi

I am trying to fit a function to my data points. The function is as follows:

y/(1-y)*exp(2*a*y) = (K*x)^(1/v)

Since the dependent variable (y) contains an exponential term, I could not make it in the form of y = 'the rest'. The work around I can think of is to treat x as the dependent variable and plot x in terms of y. However, I do not get a good fit at all, with a negative R^2 value. Increasing the iterations does not help.

Is there a better way to do this? Many thanks.

Here are some sample data points:

x = 0 1.04E-11 3.11E-11 5.19E-11 6.92E-11 1.38E-10 3.46E-10 6.92E-10 6.92E-09 3.46E-08 6.92E-08 2.77E-07

y = 0 0.201834862 0.201834862 0.23853211 0.171253823 0.146788991 0.318042813 0.333333333 0.177370031 0.623853211 0.929663609 1