High-Nuclearity Chromium–Nickel–Cyanide Clusters: An Open Cr8Ni5(CN)24 Cage and aC3-Symmetric Cr10Ni9(CN)42 Cluster Incorporating Three Forms of Cyanonickelate

Sokol, Jennifer J.; Shores, Matthew P.

doi:10.1002/1521-3757(20010105)113:1<242::aid-ange242>3.0.co;2-6

Cited by 16 publications

(3 citation statements)

References 23 publications

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“…Recognition of anions by synthetic receptors usually involves charge–charge interactions, hydrogen bonds, or coordination contacts with metals, all carefully arranged in space 1–5. Reversible encapsulation complexes, in which various anionic guests are surrounded by positively charged hosts, are well‐characterized in solution and in the solid state 6–12. Anions alone are not known to be sequestered in, or even recognized by neutral, reversibly formed capsules but, on occasion, they can be encapsulated as ion pairs 13–15.…”

Section: Binding Constants (Ka) Of Anion Encapsulation Complexes Cormentioning

confidence: 99%

Molecular Encapsulation of Anions in a Neutral Receptor

Hayashida

Shivanyuk

Rebek

2002

Angew. Chem. Int. Ed.

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Section: Binding Constants (Ka) Of Anion Encapsulation Complexes Cormentioning

confidence: 99%

Molecular Encapsulation of Anions in a Neutral Receptor

Hayashida

Shivanyuk

Rebek

2002

Angew. Chem. Int. Ed.

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“…These results show that the preparation of discrete cyano-bridged polynuclear species would require a decrease of the number of cyano groups on the B precursor. A few results have been reported in this respect in bioinorganic, organometallic, , and magnetostructural − studies. So, the monocyano building block of formula [Fe(OEP)(py)(CN)] (OEP = octaethylporphyrinate dianion and py = pyridine) was used to prepare heterobimetallic complexes containing the Fe III- CN−Cu II unit to mimic the iron−copper binuclear site in cyanide-inhibited cytochrome c oxidase and terminal quinol oxidases .…”

Section: Introductionmentioning

confidence: 99%

“…A new class of organometallic solids with cyanide as a bridge (trinuclear species, cages, and helical chains) have been reported recently, the mononuclear cyano precursors being [Cp*(dppe)Fe(CN)], [Cp*(PPh 3 ) 2 Ru(CN)], and [Cp*(M(CN) 3 ] - (M = Ir and Rh) . Very recently, nice discrete cluster analogues of the cubic cages existing in the Prussian blue type structure such as the 14-metal, [(Me 3 tacn) 8 Cr 8 Ni 6 (CN) 24 ] 12+ , and 19-metal, [(Me 3 tacn) 10 Cr 10 Ni 9 (CN) 42 ] 6+ , assemblies (Me 3 tacn = N , N ‘, N ‘ ‘-trimethyl-1,4,7-triazacyclononane) were prepared when the neutral [(Me 3 tacn)Cr((CN) 3 ] mononuclear complex was allowed to react with hydrated metal ions 24b. Finally, the dicyano 25 and tetracyano 26 low-spin iron(III) complexes of formulas [Fe(bipy) 2 (CN) 2 ] + (bipy = 2,2‘-bipyridine) and [Fe(phen)(CN) 4 ] - (phen = 1,10-phenanthroline) allowed the preparation of the cyanide-bridged cyclic tetranuclear complex [Fe 2 (bipy) 4 (CN) 4 Cu 2 (bipy) 2 ] 6+ and the isostructural double zigzag chains [{Fe(phen)(CN) 4 } 2 M(H 2 O) 2 ]·4H 2 O with M = Mn and Zn.…”

Section: Introductionmentioning

confidence: 99%

[Fe(bipy)(CN)₄]^- as a Versatile Building Block for the Design of Heterometallic Systems: Synthesis, Crystal Structure, and Magnetic Properties of PPh₄[Fe^III(bipy)(CN)₄]·H₂O, [{Fe^III(bipy)(CN)₄}₂M^II(H₂O)₄]·4H₂O, and [{Fe^III(bipy)(CN)₄}₂Zn^II]·2H₂O [bipy = 2,2‘-Bipyridine; M = Mn and Zn]

et al. 2002

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The new cyano complexes of formulas PPh(4)[Fe(III)(bipy)(CN)(4)] x H(2)O (1), [[Fe(III)(bipy)(CN)(4)](2)M(II)(H(2)O)(4)] x 4H(2)O with M = Mn (2) and Zn (3), and [[Fe(III)(bipy)(CN)(4)](2)Zn(II)] x 2H(2)O (4) [bipy = 2,2'-bipyridine and PPh(4) = tetraphenylphosphonium cation] have been synthesized and structurally characterized. The structure of complex 1 is made up of mononuclear [Fe(bipy)(CN)(4)](-) anions, tetraphenyphosphonium cations, and water molecules of crystallization. The iron(III) is hexacoordinated with two nitrogen atoms of a chelating bipy and four carbon atoms of four terminal cyanide groups, building a distorted octahedron around the metal atom. The structure of complexes 2 and 3 consists of neutral centrosymmetric [[Fe(III)(bipy)(CN)(4)](2)M(II)(H(2)O)(4)] heterotrinuclear units and crystallization water molecules. The [Fe(bipy)(CN)(4)](-) entity of 1 is present in 2 and 3 acting as a monodentate ligand toward M(H(2)O)(4) units [M = Mn(II) (2) and Zn(II) (3)] through one cyanide group, the other three cyanides remaining terminal. Four water molecules and two cyanide nitrogen atoms from two [Fe(bipy)(CN)(4)](-) units in trans positions build a distorted octahedron surrounding Mn(II) (2) and Zn(II) (3). The structure of the [Fe(phen)(CN)(4)](-) complex ligand in 2 and 3 is close to that of the one in 1. The intramolecular Fe-M distances are 5.126(1) and 5.018(1) A in 2 and 3, respectively. 4 exhibits a neutral one-dimensional polymeric structure containing two types of [Fe(bipy)(CN)(4)](-) units acting as bismonodentate (Fe(1)) and trismonodentate (Fe(2)) ligands versus the divalent zinc cations through two cis-cyanide (Fe(1)) and three fac-cyanide (Fe(2)) groups. The environment of the iron atoms in 4 is distorted octahedral as in 1-3, whereas the zinc atom is pentacoordinated with five cyanide nitrogen atoms, describing a very distorted square pyramid. The iron-zinc separations across the single bridging cyanides are 5.013(1) and 5.142(1) A at Fe(1) and 5.028(1), 5.076(1), and 5.176(1) A at Fe(2). The magnetic properties of 1-3 have been investigated in the temperature range 2.0-300 K. 1 is a low-spin iron(III) complex with an important orbital contribution. The magnetic properties of 3 correspond to the sum of two magnetically isolated spin triplets, the antiferromagnetic coupling between the low-spin iron(III) centers through the -CN-Zn-NC- bridging skeleton (iron-iron separation larger than 10 A) being very weak. More interestingly, 2 exhibits a significant intramolecular antiferromagnetic interaction between the central spin sextet and peripheral spin doublets, leading to a low-lying spin quartet.

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A Trigonal‐Bipyramidal Cyanide Cluster with Single‐Molecule‐Magnet Behavior: Synthesis, Structure, and Magnetic Properties of {[Mn^II(tmphen)₂]₃[Mn^III(CN)₆]₂}

et al. 2003

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Molecules that exhibit magnetic bistability, commonly referred to as single-molecule magnets (SMMs), are of high interest because of their unusual physical properties and potential applications in quantum computing.[1] In contrast to traditional magnets, which are characterized by the bulk ordering of spins within a 3D solid, SMM behavior arises from the intrinsic magnetic properties of the individual molecules. The signature of an SMM is a slow paramagnetic relaxation of the magnetization evidenced by a frequency-dependent outof-phase (c 00 m ) ac susceptibility signal and hysteretic behavior. The presence of an appreciable thermal barrier for reversing the magnetization is related to the combination of a large total spin ground state (S) and negative uniaxial anisotropy (D). 4 ], which displays a ground state of S = 10.[2] Since this discovery, a number of oxo-bridged clusters containing V, [3] Mn, [4][5][6] Fe, [7] Co, [8] and Ni [9] have also been shown to display SMM behavior. In all cases, the molecules that have longer paramagnetic relaxation times have values of S > 3 or higher and a negative D value.In considering the prospects for preparing non-oxide SMMs, we turned our attention to chemistry inspired by the face-centered Prussian-blue solids. The recognition that bimetallic Prussian-blue solids exhibit spontaneous magnetization at temperatures as high as 376 K [10] prompted an extrapolation of this chemistry to the realm of magnetic

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High-Nuclearity Chromium–Nickel–Cyanide Clusters: An Open Cr8Ni5(CN)24 Cage and aC3-Symmetric Cr10Ni9(CN)42 Cluster Incorporating Three Forms of Cyanonickelate

Cited by 16 publications

References 23 publications

Molecular Encapsulation of Anions in a Neutral Receptor

Molecular Encapsulation of Anions in a Neutral Receptor

A Trigonal‐Bipyramidal Cyanide Cluster with Single‐Molecule‐Magnet Behavior: Synthesis, Structure, and Magnetic Properties of {[Mn^II(tmphen)₂]₃[Mn^III(CN)₆]₂}

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High-Nuclearity Chromium–Nickel–Cyanide Clusters: An Open Cr8Ni5(CN)24 Cage and aC3-Symmetric Cr10Ni9(CN)42 Cluster Incorporating Three Forms of Cyanonickelate

Cited by 16 publications

References 23 publications

Molecular Encapsulation of Anions in a Neutral Receptor

Molecular Encapsulation of Anions in a Neutral Receptor

[Fe(bipy)(CN)4]- as a Versatile Building Block for the Design of Heterometallic Systems: Synthesis, Crystal Structure, and Magnetic Properties of PPh4[FeIII(bipy)(CN)4]·H2O, [{FeIII(bipy)(CN)4}2MII(H2O)4]·4H2O, and [{FeIII(bipy)(CN)4}2ZnII]·2H2O [bipy = 2,2‘-Bipyridine; M = Mn and Zn]

A Trigonal‐Bipyramidal Cyanide Cluster with Single‐Molecule‐Magnet Behavior: Synthesis, Structure, and Magnetic Properties of {[MnII(tmphen)2]3[MnIII(CN)6]2}

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A Trigonal‐Bipyramidal Cyanide Cluster with Single‐Molecule‐Magnet Behavior: Synthesis, Structure, and Magnetic Properties of {[Mn^II(tmphen)₂]₃[Mn^III(CN)₆]₂}