Gas storage materials and devices

The invention provides a porous metal-organic framework that can be used to store gases, such as hydrogen. Also provided is metal-organic framework comprising bifunctional metallic bridging groups and organic nodes having three or more points of connection, wherein the framework has one or more cavities suitable for containing one or more storage gas molecules. The invention further provides a metal-organic framework comprising organic functional groups directed into the one or more cavities that are capable of reacting with a storage gas.