  Within the so-called "no-man's land" between about 150 and 235 K,
crystallization of bulk water is inevitable. The glasslike freezing and a
liquid-to-liquid transition of water, predicted to occur in this region, can be
investigated by confining water in nanometer-sized pores. Here we report the
molecular dynamics of water within the pores of a metal-organic framework using
dielectric spectroscopy. The detected temperature-dependent dynamics of
supercooled water matches that of bulk water as reported outside the borders of
the no-man's land. In confinement, a different type of water is formed,
nevertheless still undergoing a glass transition with considerable molecular
cooperativity. Two different length scales seem to exist in water: A smaller
one, of the order of 2 nm, being the cooperativity length scale governing
glassy freezing, and a larger one (> 2 nm), characterizing the minimum size of
the hydrogen-bonded network needed to create "real" water with its unique
dynamic properties
