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A set of terms, definitions, and recommendations is provided for use in the classification of coordination polymers, networks, and metal-organic frameworks (MOFs). A hierarchical terminology is recommended in which the most general term is coordination polymer. Coordination networks are a subset of coordination polymers and MOFs a further subset of coordination networks. One of the criteria an MOF needs to fulfill is that it contains potential voids, but no physical measurements of porosity or other properties are demanded per se. The use of topology and topology descriptors to enhance the description of crystal structures of MOFs and 3D-coordination polymers is furthermore strongly recommended.

Coordination polymers (CPs) and metal-organic frameworks (MOFs) are among the most prolific research areas of inorganic chemistry and crystal engineering in the last 15 years, and yet it still seems that consensus is lacking about what they really are, or are not.

In this review, we highlight various preparative strategies and characterization methods for metal nanoparticles fabricated in porous metal-organic frameworks (MOFs) or porous coordination polymers (PCPs), and their applications in hydrogen storage and heterogeneous catalysis.

Novel supramolecular solids whose topologies depend on the counteranion, [Ag(C 14 H 20 N 6 )(NO 3 )] (1), [Ag(C 14 H 20 N 6 )]CF 3 SO 3 (2), and [Ag(C 14 H 20 N 6 )]ClO 4 (3), have been prepared by the self-assembly of AgX (X ) NO 3 -, CF 3 SO 3 -, and ClO 4 -) with ethylenediaminetetrapropionitrile (EDTPN, C 14 H 20 N 6 ). X-ray crystal structures indicate that compounds 1-3 are a 1-D coordination polymer, a 2-D layer, and a boxlike 2-D network, respectively. In 1, 2, and 3, the EDTPN ligand undergoes anion-dependent ligation to bind two, three, and five Ag(I) ions per EDTPN, respectively, by using the cyano groups in addition to two tertiary nitrogen atoms. The coordination numbers of Ag(I) ion in 1, 2, and 3, are five, four, and six, respectively. Interestingly, the CF 3 SO 3anion of 2 is exchanged with NO 3and ClO 4quantitatively in the crystalline state when the crystal of 2 is immersed in the aqueous solutions of NaNO 3 and NaClO 4 , respectively. The anion-exchange process is reversible between 1 and 2 but irreversible from 1 or 2 into 3. The supramolecular structural transformations among 1-3 are observed in the crystalline state, concomitant with the anion-exchange.

A porous metal-organic framework [Zn(4)O(NTB)(2)].3DEF.EtOH (1), in which (3,6)-connected nets are doubly interpenetrated to generate curved three-dimensional channels, has been prepared. Framework 1 exhibits high permanent porosity (Langmuir surface area, 1121 m(2)/g; pore volume, 0.51 cm(3)/cm(3)), high thermal stability (up to 430 degrees C), high hydrogen adsorption capacity (1.9 wt % at 77 K and 1 atm), selective organic guest binding ability (K(f)()( )(): MeOH > pyridine > benzene > dodecane), and guest-dependent blue luminescence (lambda(max) depending on guest identity). Most interestingly, the framework sustains single crystallinity even at 400 degrees C and 10(-)(5) Torr, and the framework components undergo reversible dynamics, mainly rotational motion, in response to removal and rebinding of the guest molecules.

A two-dimensional (2D) square-grid coordination polymer, {[Ni(cyclam)]2[BPTC]}n.2nH2O (1), has been assembled from [Ni(cyclam)](ClO4)2 (cyclam = 1,4,8,11-tetraazacyclotetradecane) and H4BPTC (H4BPTC = 1,1'-biphenyl-2,2',6,6'-tetracarboxylic acid) in H2O/MeOH (2.5:1, v/v) in the presence of triethylamine. When solid 1 was immersed in the EtOH solutions of AgNO3 (1.3 x 10(-1) M) and NaAuCl4.2H2O (3.4 x 10(-2) M), respectively, for 5 min at room temperature, solids including Ag (3.7 +/- 0.4 nm, diameter) and Au (2 nm, diameter) nanoparticles were formed by the redox reactions between Ni(II) ions incorporated in 1 and metal ions, as evidenced by HRTEM images, EPR, and XPS spectra. When single-crystal 1 was heated at 180 degrees C under 10(-5) Torr for 24 h, it was transformed to dehydrated compound {[Ni(cyclam)]2[BPTC]}n (2) in the single-crystal-to-single-crystal manner. The X-ray crystal structure of 2 reveals extensive dynamic motions of the molecular components in response to guest removal, involving rotation of the carboxylate and macrocycle, swing of the biphenyl, and bending of the macrocyclic coordination plane toward the carboxylate plane, which reduces the interlayer distance.

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