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Four novel polymeric coordination networks have been obtained through self-assembly processes involving alkoxo-bridged copperII species as nodes, and anionic cyano-complexes as linkers: infinity2[{Cu2(pa)2}{M(CN)2}2](M=Ag, 1; Au, 2), (infinity)3[{Cu4(mea)4}{Au(CN)2}4.H2O]3, and (infinity)3[{Cu2(pa)2}{Ni(CN)4}](pa = deprotonated propanolamine; mea = deprotonated monoethanolamine). The supramolecular architectures of compounds 1, and 2 are sustained by argentophilic or strong aurophilic interactions. The solid-state architectures of 1 and 2, which are isomorphous, consist of infinite layers, constructed from binuclear alkoxo-bridged nodes and [M(CN)2]- spacers. The layers are stacked in an offset parallel mode, and are further interconnected through Ag...Ag or Au...Au contacts (1: Ag...Ag 3.015 A; 2: Au....Au 3.069 A). Compound 3 consists of unique fourfold interpenetrating diamondoid nets. The diamondoid topology is built of heterocubane {Cu4O4} nodes, which are connected by [Au(CN)2]- rods. The Cu-O distances within the {Cu4O4} node vary between 1.927(2) and 2.679(1) A, showing unsymmetric bridging of the copper atoms. Aurophilic interactions are established between the bridging and terminal [Au(CN)2]- metalloligands, and connect the interpenetrating nets, resulting in infinite chains of gold atoms (the Au...Au distances vary between 3.253 and 3.305 [Angstrom]). Compound 4 exhibits a 3-D network constructed from {Cu2(pa)2]2+ nodes connected by square-planar [Ni(CN)4]2- ions. Compounds 1, 2 and 4 are weakly paramagnetic. The cryomagnetic investigation of reveals a gradual increase, followed by a decrease of the chiMT product, as the temperature is lowered. A superposition of ferro- (J1=+20.8 cm(-1)) and antiferromagnetic (J2=-6.4) interactions within the tetranuclear node was found. Antiferromagnetic interactions are established between the tetranuclear nodes (theta=-2.99 K).

Using bis-amidinium dications as tetra H-bond donor tectons and Au(CN)(2)(-) anion, neutral 1-D networks based on a bis monohapto mode of H-bonding are obtained. Owing to the short metal-metal distance within the network, luminescent crystals are obtained. The emission phenomena may be tuned by the nature of the spacer connecting the two cyclic amidinium groups.

9 pagesFour new cyano-bridged [Mn-II M-III Mn-II] heterotrinuclear complexes (M-III = Cr, Fe, Co) have been synthesized and crystallographically characterized: {[(H2O) L-1 Mn - NC - Cr(CN)(4) - CN-MnL1( H2O)]}(3)[Cr(CN)(6)] center dot 10H(2)O 1, [(H2O) L-2 Mn - NC - M(CN)(4) - CN - MnL2(NCS)] center dot 2H(2)O 2, [(H2O) L-2 Mn - NC - Fe(CN)(4) - CN - MnL2(H2O)](NCS) center dot 1.5H(2)O 3, and [(H2O) L-2 Mn - NC-Co( CN)(4) - CN - MnL2(H2O)](NCS) center dot 1.5H(2)O 4 (L-1 = 2,13-dimethyl-3,6,9,12,18-pentaazabicyclo[ 12.3.1] octadeca-1(18), 2,12,14,16-pentaene, L-2 = 2,13-dimethyl-6,9-dioxa-3,12,18-triazabicyclo[ 12.3.1] octadeca-1(18), 2,12,14,16-pentaene). The crystal structure of 1 consists of independent [MnCrMn] monocations whose charges are counterbalanced by [Cr(CN)(6)](3-) anions. The crystal structure of 2 consists of neutral heterotrinuclear [ MnCrMn] species, with the isothiocyanato ion coordinated to one of the manganese atoms. Compounds 3 and 4 are isomorphous. Their crystal structure consists of centrosymmetric [MnMMn] entities, uncoordinated NCS 2 ions, and solvent molecules. The magnetic properties of the four complexes have been investigated. Compounds 1 and 2 are new examples of systems with an irregular spin state structure, exhibiting the characteristic minimum on the the chi T-M versus T curves. The exchange interaction between the chromium(III) and the manganese(II) ions is antiferromagnetic (1: J = -9.8 cm(-1); 2: J = -6.52 cm(-1)). For compound 3, the exchange interaction between manganese( II) and iron( III) was found to be ferromagnetic

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The synthesis and crystallographic characterization of a new family of M(μ-CN)Ln complexes are reported. Two structural series have been prepared by reacting in water rare earth nitrates (Ln III = La, Pr, Nd, Sm, Eu, Gd, Dy, Ho) with K 3 [M(CN) [CoGd] 10). The hexamethylenetetramine molecules contribute to the stabilization of the crystals by participating in an extended network of hydrogen bond interactions. In both series the aqua ligands are hydrogen bonded to the nitrogen atoms from both the terminal CN groups and the hmt molecules. The [FeGd] complex has been analyzed with 57 Fe Mössbauer spectroscopy, EPR, and magnetic susceptibility measurements. We have also analyzed the [FeLa] complex, in which the paramagnetic Gd III is replaced by diamagnetic La III , to obtain information about the low-spin Fe III site that is not accessible in the presence of a paramagnetic ion at the complementary site. For the same reason, the [CoGd] complex, containing diamagnetic Co III , was studied with EPR and magnetic susceptibility measurements, which confirmed the S = 7/2 spin of Gd III . Prior knowledge about the paramagnetic sites in [FeGd] allows a detailed analysis of the exchange interactions between them. In particular, the question of whether the exchange interaction in [FeGd] is isotropic or anisotropic has been addressed. Standard variable-temperature magnetic susceptibility measurements provide only the value for a linear combination of J x , J y , and J z but contain no information about the values of the individual exchange parameters J x , J y , and J z . In contrast, the spin-Hamiltonian analysis of the variable-field, variable-temperature Mössbauer spectra reveals an exquisite sensitivity on the anisotropic exchange parameters. Analysis of these dependencies in conjunction with adopting the g-values obtained for [FeLa], yielded the values J x = Ŝ 1 · J · Ŝ 2 +0.11 cm −1 , J y = +0.33 cm −1 , and *To whom correspondence should be addressed emunck@cmu.edu; marius.andruh@dnt.ro; eb7g@andrew.cmu.edu. Supporting Information Available Details of the analysis of the magnetic susceptibilities, an explicit derivation of eq 1 as well as a proof for the validity of the subtraction method in the analysis of χT vs. T of [FeGd] are presented. Complete crystallographic data, structure, solution and refinement are available. This material is available free of charge via internet from http://pubs.acs.org. NIH Public AccessAuthor Manuscript Inorg Chem. Author manuscript; available in PMC 2011 April 5. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript J z = +1.20 cm −1 (convention). The consistency of these results with magnetic susceptibility data is analyzed. The exchange anisotropy is rooted in the spatial anisotropy of the low-spin Fe III ion. The condition for anisotropic exchange is the presence of low-lying orbital excited states at the ferric site that (i) effectively interact through spin-orbit coupling with the orbital ground state and (ii) have an exchange parameter with t...

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Three 1-D copper(II) coordination polymers have been obtained by using the nicotinato anion (NA-) as a bridge, and 2,2‘-bipyridine or dicyanamide (dca) as coligands:  Cu2(bipy)2(NA)2](ClO4)2·H2O 1, Cu2(Me2bipy)2(NA)2](ClO4)2 2, Cu3(NA)4(dca)2(H2O)8]·2H2O 3 (bipy = 2,2‘-bipyridine; Me2bipy = 4,4‘-dimethyl-2,2‘-bipyridine, dca = dicyanamide anion). The metal−ligand association in compounds 1 and 2 is very similar and generates tubelike coordination polymers, which are constructed from pairs of copper atoms connected through two carboxylato groups from two NA- ligands. Each pyridyl moiety from the NA- ligand coordinates at the apical position of the copper ions from another pair, resulting in chains running along the crystallographic c axis. The structure of 3 consists of infinite ladderlike chains:  the rungs are formed by trinuclear [Cu3] moieties, with the copper(II) ions connected through NA- bridges, the ladder sides being constructed from dca- bridging ligands. The cryomagnetic investigation of the three compounds reveals weak antiferromagnetic interactions mediated by the nicotinato ligand, 1:  J = −7.3 cm-1, 2: −15.3 cm-1, 3: −0.58 cm-1.