NOVELTY - Zeolitic framework (I), comprising many substituted imidazolidine compounds (II), is new.    USE - (I) is useful in a gas storage device, a catalyst substrate and in a device (preferably storage unit) for the sorptive uptake of a chemical species (where the chemical species is an adsorbed chemical species (preferably ammonia, carbon dioxide, carbon monoxide, hydrogen, amines, methane, oxygen, argon, nitrogen, organic dyes and/or polycyclic organic molecules)) (all claimed). (I) is useful: in catalysis and sensors (e.g. resistometric sensors), in petrochemical cracking, ion-exchange for water softening and purification; and for treatment of natural gas streams containing contaminants such as carbon dioxide, hydrogen sulfide and water vapor. (I) is useful in the catalytic conversion of organic molecules (reactions of this type are e.g. oxidations, epoxidation of olefins, e.g. preparation of propylene oxide from propylene and hydrogen peroxide, hydroxylation of aromatics, e.g. preparation of hydroquinone from phenol and hydrogen peroxide or the conversion of toluene into cresol).    ADVANTAGE - (I) has a thermal stability of at least up to 500 degrees C and a Langmuir surface area of 1240 m2/g-1 or 780 m2/g-1, hence has high stability and high porosity and organic functionality, which could be applied to highly efficient catalysis and separations. (I) has optimized pore size for hydrogen sorption and functionalized compounds showing good sorption capacities, which makes (I) as more selective and more efficient hydrogen storage materials.    DETAILED DESCRIPTION - Zeolitic framework (I), comprising many substituted imidazolidine compounds of formula (M-L-M) (II), is new, where (I) is M-L-M (where L comprises fused imidazolidine of formula (a) or comprises at least one L, which is (a) or at least one other L, which is imidazolidine compound of formula (b) and/or fused imidazolidine compound of formula (c)).    M = transition metal;    M1-M6 = M;    L = linking moiety;    A = C or N, where R5-R8 are present when A1 and A4 comprise C;    R1, R4, R9 = non-sterically hindering group that does not interfere with M;    R2, R3, R5, R8, R10-R12 = alkyl or halo-cyano-nitro-, and when the linking moiety comprises structure (a), R10-R12 are electron withdrawing groups; and    R6, R7 = electron withdrawing group.    INDEPENDENT CLAIMS are included for:    (1) a device for the sorptive uptake of a chemical species, comprising a sorbent having (I) for the uptake of the chemical species; and    (2) a method for the sorptive uptake of a chemical species, comprising contacting the chemical species with a sorbent comprising (I).