Deconstructing the Crystal Structures of Metal Organic Frameworks and Related Materials into Their Underlying Nets Michael O’Keeffe* and Omar M. Yaghi* Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287, United States Center for Reticular Chemistry, Center for Global Mentoring, Department of Chemistry and Biochemistry, University of California Los Angeles, 607 Charles E. Young Dr. East, Los Angeles, California 90095, United States Graduate School of EEWS, Korea Advanced Institute of Science and Technology, Daejeon, Korea

/pdf/deconstructing-the-crystal-structures-of-metal-organic-1nk1g6s2pd.pdf

Deconstructing the crystal structures of metal-organic frameworks and related materials into their underlying nets.

Photoswitchable coordination compounds

Design of single chain magnets through cyanide-bearing six-coordinate complexes

A series of bowls separated by hour-glass-shaped channels characterizes the structure of the undulating two-dimensional coordination polymer that is prepared from a nanoscale secondary building unit (nSBU), which is formed by four square metal(II)carboxylate SBUs that have 1,3-benzenedicarboxylate units as 120° spacers

Self-Assembly of Nanometer-Scale Secondary Building Units into an Undulating Two-Dimensional Network with Two Types of Hydrophobic Cavity

The study of paramagnetic compounds based on 4d and 5d transition metals is an emerging research topic in the field of molecular magnetism. An essential driving force for the interest in this area is the fact that heavier metal ions introduce important attributes to the physical properties of paramagnetic compounds. Among the attractive characteristics of heavier elements vis-a-vis magnetism are the diffuse nature of their d orbitals, their strong magnetic anisotropy owing to enhanced spin–orbit coupling, and their diverse structural and redox properties. This critical review is intended to introduce readers to the topic and to report recent progress in this area. It is not fully comprehensive in scope although we strived to include all relevant topics and a large subset of references in the area. Herein we provide a survey of the history and current status of research that has been conducted on the topic of second and third row transition metal molecular magnetism. The article is organized according to the nature of the precursor building blocks with special topics being highlighted as illustrations of the special role of heavier transition metal ions in the field. This paper is addressed to readers who are interested in molecular magnetism and the application of coordination chemistry principles to materials synthesis (231 references).

Molecular magnetic materials based on 4d and 5d transition metals.

Long-range ferromagnetic ordering at 3 K is observed for the title compound, which may be considered as a fully localized mixed-valence species (Mo(3+) and Mo(4+)) as well as a mixed-spin species (low-spin and high-spin Mn(2+) ions). Its two-dimensional structure consists of heart-shaped 48-membered rings, and each ring contains 16 metal centers (see picture).

A Mixed‐Valence and Mixed‐Spin Molecular Magnetic Material: [MnIIL]6[MoIII(CN)7][MoIV(CN)8]2⋅19.5 H2O

Two FeII-based molybdenum polycyanides, Fe2[MoIII(CN)7]·8H2O and [Fe2(H2O)4][MoIV(CN)8]·4H2O, have been synthesized.
 The compound [Fe2(H2O)4][MoIV(CN)8]·4H2O crystallizes in the tetragonal system, space group I422. There are two molybdenum sites in a distorted square antiprism arrangement, each site being surrounded by eight CN–Fe linkages. The distorted octahedral iron site is formed by four NC–Mo linkages and two water molecules in apical
 positions. The structure is three-dimensional and highly symmetrical. The magnetic characteristics
 of these two compounds were compared. Fe2[MoIII(CN)7]·8H2O orders below 65 K as a ferrimagnet, but [Fe2(H2O)4][MoIV(CN)8]·4H2O shows no evidence of long-range magnetic order, obviously due to the contribution of the diamagnetic
 MoIV which suppresses the propagation of magnetic interaction between adjacent iron(II) ions through CN bridges.
 The results are discussed in the light of the single-crystal
 structural features of [Fe2(H2O)4][MoIV(CN)8]·4H2O.

Hepta/octa cyanomolybdates with Fe2+: influence of the valence state of Mo on the magnetic behavior

Example of a single trans-azido-bridged Mn(II) chain: synthesis, structural and magnetic characteristics

Eine ferromagnetische Fernordnung bei 3 K weist die Titelverbindung auf, die sowohl als eine vollstandig lokalisiert gemischtvalente Spezies (Mo3+ und Mo4+) wie auch als eine Spezies mit gemischten Spins (Low-spin- und High-spin-Mn2+-Ionen) beschrieben werden kann. Ihre zweidimensionale Struktur besteht aus herzformigen, 48gliedrigen Ringen mit jeweils 16 Metallzentren (siehe Bild).

Ein gemischtvalentes molekulares magnetisches Material mit gemischtem Spin: [MnIIL]6[MoIII(CN)7][MoIV(CN)8]2⋅19.5 H2O

We report the synthesis of the compound [Mn(tacn)]2[Mo(CN)7]·5H2O, another addition to the family of MnMo-heptacyanates It is obtained by capping the Mn(II) with the ligand ‘tacn’ (triazacyclononane) and reacting it with the [MoIII(CN)7]4− precursor It exhibits ferromagnetic behavior below 90 K

A. K. Sra

Papers

A Mixed‐Valence and Mixed‐Spin Molecular Magnetic Material: [MnIIL]6[MoIII(CN)7][MoIV(CN)8]2⋅19.5 H2O

Hepta/octa cyanomolybdates with Fe2+: influence of the valence state of Mo on the magnetic behavior

Example of a single trans-azido-bridged Mn(II) chain: synthesis, structural and magnetic characteristics

Ein gemischtvalentes molekulares magnetisches Material mit gemischtem Spin: [MnIIL]6[MoIII(CN)7][MoIV(CN)8]2⋅19.5 H2O

[Mn(tacn)]2Mo(CN)7·5H2O: a 90 K ferromagnet