Stacked metal complexes: Structures and properties

Abstract

We discuss the structural aspects of crystals that contain molecular stacks and are comprised of two components, at least one of which is a planar transition-metal chelate complex. One of the components may be viewed as an electron donor, D, or its cation, D ÷p, the other an acceptor, A, or its anion, A -q. In these crystals either one or both components tend to form stacks, and we employ a classification scheme whose first major division is structural: crystals either contain stacks that integrate the D and A units, or the D and A units can be segregated with D or A stacking, or both. The second major division is physical. In an integrated stack crystal the metal-ligand complex is either neutral or ionic; in a segregated stack crystal it either has an integral oxidation state or a nonintegral oxidation state. The non-integral oxidation state is sometimes referred to as "partial oxidation", "mixed valence", or "incomplete charge transfer".The compounds discussed here exhibit a broad range of fascinating properties. Some of these compounds are primarily of structural interest, while others have unusual magnetic properties. Yet others, particularly those involving metallomacrocycles, exhibit high or unusual electrical conductivities.By classifying and comprehensively reviewing the structural data available, we hope to provide a firmer basis for improving the understanding of the relation between the physical properties and the structural features of these compounds.

Structural, electrical, magnetic, and optical properties of bis-benzene-1,2-dithiolato-Au(IV) crystals

“…[1][2][3][4][5] Within this family the Ni-and Cugroup dithiolenes are all planar and exhibit a wide range of physical behavior, including metallicity and superconductivity. 6 An example of the latter is the wellknown tetrathiafulvalene ͑TTF 2 ͒ Ni͑dmit͒ 2 , where dmit denotes 4,5-dimercapto-1,3-dithiole-2-thione. 7 The gold-dithiolene complexes-though much less studied than the Ni dithiolenes-are known in a range of oxidation states.…”

Bleihalogenide ungewöhnlicher Zusammensetzung und Struktur1: Iodid von Wells K2PbI4/2I2· 2 H2O · xKI3 ^H2O (x = 0,237, y = 0,37)

“…Coppens, 1982;Ibers, Pace, Martinsen, Hoffman, 1982;Kertesz, Vonderviszt, 1982; und die dort zitierte Literatur). Coppens, 1982;Ibers, Pace, Martinsen, Hoffman, 1982;Kertesz, Vonderviszt, 1982; und die dort zitierte Literatur).…”

Synthesis, crystal structure and charge transport properties of one-electron oxidized zirconium diphthalocyanine, [ZrPc2]IBr2

“…Partial oxidation by iodine of phthalocyaninato-like metallomacrocyclic complexes has yielded a series of onedimensional highly conducting molecular materials [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. Generally, the electrical properties of these materials are strictly connected with the structural and electronic features of the macrocyclic ring, which is the site of the extensive pelectron delocalisation, as well as on the nature and the electronic structure of the central metal ion [4]. The majority of the partially oxidized metallophthalocyaninato complexes crystallise in the tetragonal system and retain a single struc-tural motif that consists of metal-over-metal pseudo-monodimensional columnar stacks of partially oxidized MPc d+ units surrounded by linear chains of symmetrical triiodide anions [6].…”