  We present the results of a computer simulation study of thermodynamical
properties of TIP4P water confined in a hydrophobic disordered matrix of soft
spheres upon supercooling. The hydrogen bond network of water appears preserved
in this hydrophobic confinement. Nonetheless a reduction in the average number
of hydrogen bonds due to the geometrical constraints is observed. The liquid
branch of the spinodal line is calculated from 350 K down to 210 K. The same
thermodynamic scenario of the bulk is found: the spinodal curve is
monotonically decreasing. The line of maximum density bends avoiding a crossing
of the spinodal. There is however a shift both of the line of maximum density
and of the spinodal toward higher pressures and lower temperatures with respect
to bulk.
