Low temperature process for the synthesis of mof carboxylate nanoparticles

A microwave-free process for preparing nanoparticles of porous crystalline Fe-, Al- or Ti-based MOF carboxylate material with low polydispersity index, comprising steps of:

• A) mixing in an aqueous solvent system:
• (i) at least a first inorganic metallic precursor in the form of a metal M, a salt of a metal M or a coordination complex comprising the metal ion M2+ selected from Fe2+, Fe3+, Ti3+, Ti4+ or Al3+;
• (ii) at least one precursor ligand L′ different from carboxylate salt and having the structure R1—(C(═O)—R3)q wherein:
• q represents an integer from 2 to 6;
• preferably q represents 2, 3 or 4;
• each occurrence of R3 is independently selected from a halogen atom, —OH, —OR4, —O—C(═O)R3A or —NR3AR3B, wherein R3A and R3B, identical or different, represent C1-12 alkyl radicals;
• R1 independently represents:
• (a) a C1-12alkyl, C2-12alkenyl or C2-12alkynyl radical;
• (b) a fused or non-fused monocyclic or polycyclic aryl radical, comprising 6 to 50 carbon atoms;
• (c) a fused or non-fused monocyclic or polycyclic heteroaryl, comprising 4 to 50 carbon atoms;
• R1 optionally bearing one or more substituents independently selected from
• a halogen atom, —OH, —NH2, —NO2 or C1-6alkyl;
• each occurrence of R4 independently represents —OH, a halogen atom, or a —OR5, —O—C(═O)R5 or —NR5R5′ moiety, wherein R5 and R5′ independently represent C1-12alkyl;
• and
• B) allowing the mixture obtained in step A) to react at a temperature at least 10° C. below the boiling point temperature of the aqueous solvent system;
• so as to obtain the said nanoparticles;
• wherein the process is carried out in the absence of acid or base additives.