Transition metals with organic ligands

Molecular Metal Complexes Compounds of this type do not form delocalized electronic bands in the sohd state, and their color is due to intramolecular electronic transitions. Many complexes of transition metals with organic ligands belong to this class. complexes with phenanthroline (red/colorless) and Ru + + with 2,2 -... 

The reduction of transition metals with organic ligands has been the subject of a... 

Many complexes of metals with organic ligands absorb in the visible part of the spectrum and are important in quantitative analysis. The colours arise from (i) d- d transitions within the metal ion (these usually produce absorptions of low intensity) and (ii) n->n and n n transitions within the ligand. Another type of transition referred to as charge-transfer may also be operative in which an electron is transferred between an orbital in the ligand and an unfilled orbital of the metal or vice versa. These give rise to more intense absorption bands which are of analytical importance. 

Coordinate covalent bonds involve the unequal sharing of an electron pair by two atoms, with both electrons (originally) coming from the same atom. The electron pair donor is the ligand, or Lewis base, whereas the acceptor is the central atom (because it frequently can accept more than one pair of electrons), or Lewis acid. These bonds are important in all interactions between transition metals and organic ligands (e.g., Fe + in hemoglobin and the cytochromes). 

Here we show that the rectangular molecular boxes composed of transition metals and organic ligands are predictably and quantitatively catenated if the boxes involve parallel aromatic rings with an interplanar separation of 3.5 A. 

Electron nuclear double resonance of transition metal complexes with organic ligands. A. Schweiger, Struct. Bonding (Berlin), 1982, 51, 1-119 (294). 

Recent results in the chemistry of transition metal clusters with organic ligands. H. Vahrenkamp, Struct. Bonding (Berlin), 1977, 32, 2-56 (408). 

Schweiger A (1982) Electron Nuclear Double Resonance of Transition Metal Complexes with Organic Ligands. 51 1-122 Scozzafava A, see Bertini I (1982) 48 45-91... 

Vahrenkamp H (1977) Recent Results in the Chemistry of Transition Metal Clusters with Organic Ligands. 32 1-56... 

Complexes of metals with organic and inorganic ligands which absorb in the visible region of the spectrum are of importance in quantitative analysis. Transitions giving rise to coloured complexes are of three types ... 

Electron Nuclear Double Resonance of Transition Metal Complexes with Organic Ligands... 

This section covers the literature of ENDOR on transition metal complexes with organic ligands through the end of 1980. The discussion also includes unpublished results and papers submitted for publication which came to our knowledge. Only contributions for which ENDOR spectroscopy yields either new or significantly improved results compared with the data obtained from EPR measurements will be discussed in more detail. 

---