Clive E. Holloway

COPPER(II) COORDINATION COMPOUNDS: CLASSIFICATION AND ANALYSIS OF CRYSTALLOGRAPHIC AND STRUCTURAL DATA III. DIMERIC COMPOUNDS

Abstract This review summarizes the data for over nine hundred dimeric Cu(II) coordination compounds. There are several types of the bridges, from which doubly bridges by far prevail. The most common ligands are O− and N− donors. From the stereochemical point of view, a square-pyramidal arrangement with different degrees of distortion about Cu(II), is the most common. Several relationships were found between the Cu-Cu distances and the Cu-L-Cu bridge angle and the type of bridging, between the intra-ligand L-Cu-L ring angles and coordination numbers.

Spectral study of copper(II) flufenamates: crystal and molecular structure of biis(Flufenamato)DI(N,N-diethylnicotinamide)Di(Aqua)copper(II)

Abstract New copper(II) flufenamate (flu) compounds of the composition Cu(flu) 2 L (L=papaverine or caffeine) and Cu(flu) 2 L 2 [L=nicotine, nicotinamide, N,N -diethylnicotinamide (Et 2 nia), pyridine-2,6-dimethanol or methyl-3-pyridylcabamate] have been prepared. The spectroscopic properties of Cu(flu) 2 L indicate the presence of copper(II) dimers structurally similar to those in copper(II) acetate monohydrate. All the Cu(flu) 2 L 2 compounds seem to possess octahedral copper(II) stereochemistry with differing tetragonal distortions. An X-ray analysis of Cu(flu) 2 (Et 2 nia) 2 (H 2 O) 2 was carried out, and it featured tetragonal bipyramidal geometry around the copper(II) atom. The tetragonal plane is created by flufenamate anions bonded to the copper(II) atom via the unidentate car☐ylate oxygen atoms [Cu O(3) = 196.1(2) om], the pyridine ring nitrogen atoms of the neutral ligand N,N -diethylnicotinamide [Cu N(1) = 200.1(3) pm] and axial water molecules [Cu O(2) = 244.9(4) pm].

REVIEW: ZINC(II) COMPOUNDS: CLASSIFICATION AND ANALYSIS OF CRYSTALLOGRAPHIC AND STRUCTURAL DATA

Abstract Zinc has a relatively low abundance in nature (10−6 of the earths crust) but the chemistry of zinc compounds has been extensively investigated, and the relation-ships between structure and biomedical activity are of major importance. Zinc appears to bc one of the more biologically important metals,1 second only to iron among the heavy metals (i.e. excluding sodium, potassium, magnesium and calcium).

COPPER(II) COORDINATION COMPOUNDS: CLASSIFICATION AND ANALYSIS OF CRYSTALLOGRAPHIC AND STRUCTURAL DATA II. MONONUCLEAR-, HEXA-, HEPTA-AND OCTACOORDINATE COMPOUNDS

Abstract This review summarizes the data for over five hundred and fifty six-, seven- and eight-coordinate Cu(II) coordination compounds. The six-coordinate derivatives are mostly distorted tetragonal (elongation along a single C 4 axis). The seven-coordinate derivatives are only penta-gonal-bipyramidal with different degrees of distortion and the eight-coordinate complexes are dodecahedral. The most common ligands are O- and N-donors. There is a trend for the Cu-L distance to increase with covalent radius of the coordinated atom and also increasing coordination number. In general, Cu(II) compounds “prefer” a monoclinic class and are blue or green. Several relationships were found and discussed. The data are compared and discussed with those of four- and five-coordinate Cu(II) compounds.

COPPER (II) COORDINATION COMPOUNDS: CLASSIFICATION AND ANALYSIS OF CRYSTALLOGRAPHIC AND STRUCTURAL DATA

Abstract This review summarizes the data for over twelve hundred four - and five - coordinate copper(II) coordination compounds. The four-coordinate derivatives are mostly distorted square-planar. The five-coordinate derivatives are mostly square-pyramidal. The most common ligands are oxygen- and nitrogen- donors. There is a trend for the Cu-L distance to increase with covalent radius of the coordinated atom and also increasing coordination number. There are three types of isomerism - distortion, cis- and trans- and configuration. Several relationships are found and discussed.

LEAD COORDINATION AND ORGANOMETALLIC COMPOUNDS: CLASSIFICATION AND ANALYSIS OF CRYSTALLOGRAPHIC AND STRUCTURAL DATA

This review covers over three hundred and sixty coordination and organometallic complexes of lead. About 20% of these contain lead in its +4 oxidation state, of which one fifth are dilead(+6) units, and two are anionic clusters. The Pb(IV) derivatives are predominantly organometallic, many stabilized by sandwich ligation. The majority of the Pb(ll) compounds are typical coordination complexes. Monto polynuclear derivatives are found, with coordinations numbers from 2 to 12. The effect of the non bonded pair of valence electrons is observed in lower coordination number Pb(ll) complexes. Examples of distortion, geometric and coordination isomerism are observed. Factors affecting bond lengths and bond angles are discussed, and some ambiguities in coordination polyhedra are outlined.

TIN ORGANOMETALLIC COMPOUNDS: CLASSIFICATION AND ANALYSIS OF CRYSTALLOGRAPHIC AND STRUCTURAL DATA: PART 1. MONOMERIC DERIVATIVES

This review collects together the crystallographic data of organotin compounds by type and complexity, with a view to identifying correlations between properties and structure. Because of the large number of such structures, this first part deals only with monomeric derivatives, which covers almost one thousand structural determinations. While coordination numbers range from two to eight, for two and three coordination only tin(ll) compounds are found. All others are tin(IV) except for four examples with coordination number four, and ten with coordination number five. The predominant geometries are tetrahedral, trigonal bipyramidal, pseudo-octahedral and pentagonal bipyramidal. The most common C-donor ligands are methyl and phenyl. There are examples of distortion and structural isomerism. CONTENTS 0. ABBREVIATIONS

Organoaluminium compounds: Classification and analysis of crystallographic and structural data

Abstract This review covers the organometallic derivatives of aluminium. There are two associated reviews which cover inorganic and heterometallic aluminium complexes. There are over 350 of organoaluminium X-ray crystallographic studies in which aluminium is found almost exclusively in the +3 oxidation state. The most common geometry around aluminium is tetrahedral, but other arrangements with from three to ten donor sites are also found. Dimeric derivatives are the most common, followed by monomeric derivatives. Higher degrees of oligomerization are also found, but there are only three examples which can be classified as polymers. Several examples exhibit metallic bonding between aluminium atoms. While the most common carbon-bonded ligand is the methyl group, a variety of other organic ligands are observed, including π -bonding moieties. The structures are classified according to structural type, and correlations between bonding parameters are noted.

SILVER COORDINATION AND ORGANOMETALLIC COMPOUNDS: CLASSIFICATION AND ANALYSIS OF CRYSTALLOGRAPHIC AND STRUCTURAL DATA

Abstract This review summarizes the data for almost six hundred silver coordination and organometallic compounds, with the silver atom occurring in oxidation states of +1, +2, and two examples of +3 in a square-planar environment. The +2 oxidation state is found in digonal, square-planar, tetrahedral and hexa-coordinated environments. The +1 oxidation state is by far the most common in various geometries from two to seven. The nuclearity range from mono- to polynuclear utilizing a variety of ligand types. There are several examples of distortion isomerism, and a few examples of polymerization isomerism. Correlations between bond lengths, bond angles, ligating atom radius and silver oxidation state are discussed.

TIN COORDINATION COMPOUNDS : CLASSIFICATION AND ANALYSIS OF CRYSTALLOGRAPHIC AND STRUCTURAL DATA

This review covers over five hundred and seventy coordination compounds of tin, of which about two thirds contain tin in its +4 oxidation state. Almost two hundred of the remainder are divalent tin compounds of which there are three ditin(+6) cations. The balance is made up of three mixed valence compounds, and several anionic clusters. The Sn(IV) derivatives are predominantly pseudo octahedral monomers. The Sn(ll) derivatives have a more varied geometry because of the sterochemical influence of the lone pair of electrons. In all cases the most common ligand donor atoms are nitrogen and oxygen. Examples of distortion, geometric and coordination isomerism are observed, with the first type being most common. The extent of metal-metal bonding and factors affecting bond lengths and bond angles are discussed. Correlations between tin valence, donor atom radius and ligand size and type are discussed.