We study the nonlinear Schr\"odinger equation for the sβfractional
pβLaplacian strongly coupled with the Poisson equation in dimension two and
with p=s2β, which is the limiting case for the embedding of the
fractional Sobolev space Ws,p(R2). We prove existence of
solutions by means of a variational approximating procedure for an auxiliary
Choquard equation in which the uniformly approximated sign-changing logarithmic
kernel competes with the exponential nonlinearity. Qualitative properties of
solutions such as symmetry and decay are also established by exploiting a
suitable moving planes technique