Chemo-switched chromatic, magnetic and structural changes with retention of molecular crystallinity, Ni(12aneS4)(BF4)2.

The molecular crystal [Ni(12aneS(4))](BF(4))(2) (12aneS(4) = 1,4,7,10-tetrathiacyclododecane) displays the uncommon ability to retain its crystallinity on facile reversible hydration/dehydration without requiring polymeric bonding and despite the significant structural changes required. The flexibility of the 12aneS(4) ring facilitates rearrangement of the complex in the solid state upon absorption of two equivalents of water, with the crystal structures showing a clear topotactic relationship. The well defined chromatic, structural and magnetic changes that are both highly sensitive and easily reversed makes this complex of interest as an environmentally responsive material and as a contrasting example to the commonly reported coordination polymers.

A multifaceted approach to hydrogen storage.

The widespread adoption of hydrogen as an energy carrier could bring significant benefits, but only if a number of currently intractable problems can be overcome. Not the least of these is the problem of storage, particularly when aimed at use onboard light-vehicles. The aim of this overview is to look in depth at a number of areas linked by the recently concluded HYDROGEN research network, representing an intentionally multi-faceted selection with the goal of advancing the field on a number of fronts simultaneously.

Hexaaquanickel(II) disulfato(1,4,8,11-tetraazacyclotetradecane)nickelate(II) dihydrate.

The title compound, [Ni(H(2)O)(6)][Ni(SO(4))(2)(C(10)H(24)N(4))].2H(2)O, is an unusual compound in that it is composed of a hexaaqua complex, formally a dication, and a mixed-donor complex (four N and two O atoms), formally a dianion, with substantial charge separation between the two nickel centres (6.536 A).