Three-Dimensional Mixed-Ligand Coordination Polymers with Ferromagnetically Coupled Cyclic Tetranuclear Copper(II) Units Bonded by Weak Interactions

Abstract

b S Supporting Information ' INTRODUCTIONResearch in metalÀorganic frameworks in recent years has been given impetus by the growth of two other closely related areas: crystal engineering and metallosupramolecular chemistry. 1 Crystal engineering seeks to understand why molecules pack in the ways that they do and to use that knowledge to deliberately engineer the arrangements of molecules in new materials. 2 This is important because the properties of materials are often governed by the way in which their constituent molecules are arranged. Control over this arrangement gives control over the properties of the material. The aim of supramolecular chemistry is similar, that is, to create assemblies of molecules. The process does not involve creating structures one atom at a time, but the design of molecules that, when combined, spontaneously self-assemble in a predetermined fashion to give larger architectures. 3 Coordination compounds with appropriate metalÀligand combinations are used to create molecular building blocks for self-organized systems with diverse topologies and potential applications. 4 In addition to covalent linkages between the building blocks, noncovalent intermolecular interactions ranging in strength from very strong hydrogen bonding to weak CÀH 3 3 3 A hydrogen bonds, 5 π interactions, 6 and, ultimately, van der Waals forces direct the formation of self-assembled structures of variable dimensions. 7 In particular, there has been considerable interest in the properties of polynuclear copper(II) complexes in order to understand the relationship between structure and magnetic properties. 8 Copper(II) complexes are also of interest because of their relevance as active site structures of metalloproteins. 9 It is well-known that a carboxylate group can bridge two metal ions to give rise to a wide variety of polynuclear complexes ranging from discrete entities to three-dimensional (3D) systems. 10 In these complexes, a carboxylate group can assume many types of bridging conformations, and, as expected, the magnetic properties

Cu(ii) 3,5-diiodosalicylate complexes: precursor-dependent formation of mono-, di-, tri- and tetranuclear compounds and 1D coordination polymers

“…This motif is rare in Cu carboxylates – similar patterns were earlier encountered only in heteroleptic lactate complexes. 55…”

Diverse Coordination Chemistry of the Whole Series Rare-Earth L-Lactates: Synthetic Features, Crystal Structure, and Application in Chemical Solution Deposition of Ln2O3 Thin Films

“…Although L-lactic acid (henceforth HLact) is widely used in modern chemistry and chemical technology, simple metal salts of HLact remain poorly studied. There are few reports on the synthesis and characterization of Zn [26][27][28], Co [29], Mn [30], Zr [31], and UO 2 2+ [32] lactates or the heterocationic and mixed-ligand compounds K 2 [{VO(O 2 )(Lact )} 2 ] [33], (NH 4 ) 2 [Ti(Lact ) 3 ] [34], (NEt 4 ) 2 [VO 2 (Lact )] 2 and (Ph 3 P=N=PPh 3 ) 2 [VO 2 (Lact )] 2 [35], (TMA) 3 [Mn 2 (Lact)(Lact ) 4 ]•H 2 O [36] (TMA = NMe 4 + ), Zr(OH)Lact 3 [31], (NH 4 ) 4 [Ta 2 (Lact') 4 (O 2 ) 2 O]•3H 2 O [37], [Cu(Lact)Cl(dipyam)] (dipyam = 2,2 -dipyridylamine) [38], [Cu(Lact) (ClO 4 )(phen)] 4 (phen = 1,10-phenanthroline) [39], [Ni 6 (Lact') 2 (Lact) 2 Piv 6 (HPiv) 8 ]•2HPiv (HPiv = pivalic acid) [40], [Cu(Lact) 2 (SS)]•4H 2 O, and [Cu 2 (Lact) 4 (SCS) 3 ] (SS = 4,4dipyridyldisulfide; SCS = bis(4-pyridylthio)methane) [41] (here, Lact' corresponds to the lactic acid dianion CH 3 CH(O -)COO -). Among RE lactates, only a few compounds have been synthesized and characterized to date.…”

Binuclear, tetranuclear and hexadecanuclear thio-oxomolybdenum(v/iv) glycolates with selective adsorptions of gases

“…6 It appears in life and production, from cosmetics and skin care to polymers, which are reflected as indispensable chemical commodities. [7][8][9][10][11][12] Glycolates can chelate with metals in different ways, [13][14][15][16] especially coordinated with molybdenum. 17,18 This interest mainly stems from biological significances, 19,20 which attracts us for the further studies of their interactions with molybdenum.…”

“…As observed from 13-18, we can find that carboxyl oxygens in coordinated glycolates tend to occupy the trans positions. The Mo-O α-carboxy distances[2.221(3) av Å in[14][15][16][17][18] affected by the antisite effect are about 0.12 Å longer than the unaffected bonds[2.103(4) av Å in 1-13]. In addition, when the oxygens in the α-alkoxy groups were used as bridging atoms as in 3, 4, 11 and 12, the Mo-O α-alkoxy distances also show a slight increase by the trans-position effect.…”