Novel class of transition metal coordination compounds with macrocyclic organosiloxanolate ligands; their synthesis and crystal structure

Igonin, V. A.; Shchegolikhina, Olga I.; Lindeman, Sergey V.; Levitsky, Mikhail M.; Struchkov, Yuri T.; Zhdanov, A. A.

doi:10.1016/0022-328x(92)83129-6

Cited by 97 publications

(49 citation statements)

References 3 publications

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“…In contrast to the phenyl analogues previously reported, [4,6,8] the present complex has methyl groups as substituents at the silicon atoms. Preliminary results of this work have been published in ref.…”

Section: } 2 ]·5buoh}·3contrasting

confidence: 62%

“…Within the ring, the adjacent Cu 2+ ions are linked by pairs of siloxanolate oxygen atoms, which provide the main magnetic exchange path for the copper S = 1/2 spins. The overall molecular building topology is analogous to that of the hexacopper(II) cyclohexaphenylsiloxanolates [Cu 6 {(PhSiO 2 ) 6 } 2 ]· 6EtOH, [4] {[Cu 6 {(PhSiO 2 ) 6 } 2 ]·6DMF}·4DMF [6] and {[Cu 6 -{(PhSiO 2 ) 6 } 2 ]·5BuOH}·3…”

Section: Resultsmentioning

confidence: 98%

“…[4][5][6]12,13] Similarly, the novel copper methylsiloxane [Cu 6 {(MeSiO 2 ) 6 } 2 ]·6DMF (E) has been obtained in a twostep reaction (Scheme 1). The first step involves an alkaline Scheme 1.…”

Section: Resultsmentioning

confidence: 98%

“…It should be noted that in a subfamily of copper-containing organosiloxanes with N = 6, only three representatives of hexanuclear copper(II) siloxanes with phenyl substituents at silicon atoms, [Cu 6 {(PhSiO 2 ) 6 } 2 ]·6EtOH, {[Cu 6 {(PhSiO 2 ) 6 } 2 ]·6DMF}·4DMF and {[Cu 6 {(PhSiO 2 ) 6 } 2 ]·5BuOH}· 3 n BuOH, have been described in the literature. [4,6,8] For the previously reported ring-shaped molecular complex [Cu 6 {(PhSiO 2 ) 6 } 2 ]·6EtOH, [9] it was demonstrated that the six copper ions within the ring are ferromagnetically coupled (J/k B = -60 K) with a total spin S tot = 3 ground state. The complex {[Cu 6 {(PhSiO 2 ) 6 …”

Section: Introductionmentioning

confidence: 98%

“…In the past decades, some representatives of this family have been obtained and their molecular structures have been established by single-crystal X-ray analysis. [4][5][6][7][8] These clusters are composed of two 2N-membered (N Si + N O) cycloorganosiloxanolate fragments linked together through N metal atoms. These polymetallaorganosiloxane complexes offer the potential to study the magnetic properties of molecular quantum rings experimentally.…”

Section: Introductionmentioning

confidence: 99%

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Synthesis, Structure and Magnetic Properties of a Novel Hexanuclear Copper Methylsiloxane Complex

et al. 2007

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A new hexanuclear copper(II) sandwich complex based on two 12-membered macrocyclic methylsiloxanolate ligands, [Cu 6 {(MeSiO 2 ) 6 } 2 ]·6DMF, was synthesized and characterized by single-crystal X-ray diffraction analysis and magnetic measurements. The cluster compound crystallizes in the monoclinic system, space group P2 1 /n (No. 14), with a = 13.3728(5) Å, b = 15.4281(7) Å, c = 17.4335(7) Å, β = 98.932(3)°and Z = 2. The unit cell contains two identical molecular clusters, each consisting of six interacting Cu 2+ (S = ½) ions. Within the cluster the six oxygen-bridged Cu 2+ ions are arranged in an almost regular hexagon. An analysis of the high-temperature part of the magnetic susceptibility re-

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Section: } 2 ]·5buoh}·3contrasting

confidence: 62%

Section: Resultsmentioning

confidence: 98%

Section: Resultsmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

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Synthesis, Structure and Magnetic Properties of a Novel Hexanuclear Copper Methylsiloxane Complex

et al. 2007

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Towards Stepwise Cluster Assembly: A Decacopper(II) Complex Obtained by Controlled Expansion of a Metallasiloxane Cage

Abbati

Caneschi

Cornia

et al. 2002

Angew. Chem. Int. Ed.

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The synthesis of new magnetic clusters with unprecedented spin topologies is a central topic in the field of molecular magnetism. Among different strategies that have been developed, serendipitous assembly [1] and rational design [2] represent opposite limiting approaches. The rational construction of heptanuclear clusters with high-spin ground states has been reported starting from hexacyanometalates [M(CN) 6 ] 3À (M ¼ Cr, Fe) and mononuclear complexes bearing a capping ligand. [2] The use of robust, preformed clusters as central cores represents an even more appealing approach, which we are currently pursuing. In particular, we are focusing on metallasiloxane cages such as [Cu 6 {(PhSiO 2 ) 6 } 2 L 6 ] [3] (where L ¼ monodentate ligand). The [Cu 6 {(PhSiO 2 ) 6 } 2 ] skeleton features a layer of six coplanar metal ions, sandwiched between two [(PhSiO 2 ) 6 ] 6À ligands. Similar architectures containing other first-row divalent metal ions and encapsulating a chloride ion are known. [3a, 4] The twelve six-membered chelate rings in the [Cu 6 {(PhSiO 2 ) 6 } 2 ] structure convey a remarkable inertness and thermodynamic stability to the cluster core. In contrast, the monodentate ligands which surround the Cu 6 cage are labile and can be easily replaced in solution by open-shell units bearing suitable bridging groups. In principle, this allows a fully controlled organization of a second shell of magnetic centers around the Cu 6 unit, Figure 1.Herein we report the successful expansion of the hexacopper(ii) cage 1 through the addition of four [Cu(tmpa)CN] þ (tmpa ¼ tris(2-pyridylmethyl)amine) [5, 6] units from 3 to give a decacopper(ii) cluster 2. ½Cu 6 fðPhSiO 2 Þ 6 g 2 ðnBuOHÞ 6Àx ðH 2 OÞ x 1 ½CuðtmpaÞCNPF 6 3 ½Cu 6 fðPhSiO 2 Þ 6 g 2 fNCCuðtmpaÞg 4 ðPF 6 Þ 4 2 Compound 2 was synthesized by reaction of 1 [3b] with the copper cyanide complex 3 [5a] in a methanol±chloroform solvent mixture (see Experimental Section).The composition of the crystalline compound, 2¥2 CHCl 3 ¥ 2.75 MeOH¥0.25 H 2 O, was established by elemental analysis and a low-temperature single-crystal X-ray diffraction investigation. The molecular structure of the cation of 2 has idealized D 2 point-group symmetry (Figures 2 and 3). The metal topology comprises an hexagonal, almost planar Cu 6 array (within AE 0.0108(6) ä), plus four peripheral Cu(tmpa) units linked to the central core through cyanide bridges. Formation of the cyanide bridge induces only minor structural changes in the [Cu(tmpa)CN] þ unit, the bond lengths of which are equal to within 3s of those in 3. On the other hand, the trigonal-bipyramidal (TB) coordination geometry of the copper(ii) ion of 2 is slightly more distorted, with t values [7] in the range 0.843(7)±0.902 (7), compared with 0.943(3) in 3.[5a] The arrangement of the bulky Cu(tmpa) units around the Cu 6 core of 2 results in significant departures from linearity in the Cu-N-C-Cu(tmpa) moieties, which have a cisoid conformation with N-C-Cu(tmpa) and Cu-N-C angles in the range 168.8(7)±

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Molecular Recognition and Host–Guest Interactions

Haiduc

Edelmann

1999

Supramolecular Organometallic Chemistry

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Macrocyclic organomercury compounds have been known for some time, but their ability to bind anionic guests in their cavity was demonstrated relatively recently. This molecular recognition process is somewhat similar to the formation of the crown ether complexes, except that the binding sites of the macrocycle are occupied by metal atoms, able to function as Lewis acids, and therefore to bind halogen and other Lewis base anions. This approach is only in its beginnings and the recent discovery of mercuracarbaboranes as anion binding cyclic receptors gave a new impetus to research in the field.One of the earliest known organomercury macrocycles was the trimer of ovthophenylene mercury, (o-CgH4Hg)3, known from X-ray diffraction studies to have a planar cyclic structure, 1 [I, 21. It has recently been found, with the aid of 199Hg NMR spectroscopy, that this compound forms complexes with halide anions (Cl-, Br-and I-) in dichloromethane solution, but the complexes could not be isolated in solid state [3]. The fluorinated analog (o-CgF4Hg)3, 2, is a much better electron acceptor and forms stable complexes with the same halide anions; these could be 1 2 2.

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Novel class of transition metal coordination compounds with macrocyclic organosiloxanolate ligands; their synthesis and crystal structure

Cited by 97 publications

References 3 publications

Synthesis, Structure and Magnetic Properties of a Novel Hexanuclear Copper Methylsiloxane Complex

Synthesis, Structure and Magnetic Properties of a Novel Hexanuclear Copper Methylsiloxane Complex

Towards Stepwise Cluster Assembly: A Decacopper(II) Complex Obtained by Controlled Expansion of a Metallasiloxane Cage

Molecular Recognition and Host–Guest Interactions

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