  Liquids under confinement differ in behavior from their bulk counterparts and
can acquire properties that are specific to the confined phase and linked to
the nature and structure of the host matrix. While confined liquid water is not
a new topic of research, the past few years have seen a series of intriguing
novel features for water inside nanoscale pores. These unusual properties arise
from the very specific nature of nanoporous materials: termed "soft porous
crystals", they combine large-scale flexibility with a heterogeneous internal
surface. This creates a rich diversity of behavior for the adsorbed water, and
the combination of different experimental characterization techniques along
with computational chemistry at various scales is necessary to understand the
phenomena observed, and their microscopic origins. The range of systems of
interest span the whole chemical range, from the inorganic (zeolites,
imogolites) to the organic (microporous carbons, graphene and its derivatives)
and even encompass the hybrid organic--inorganic systems (such as
metal--organic frameworks).
