Bidentate phenanthroline

A bidentate phenanthroline would involve considerable non-bonding interactions between the tertiary phosphines and the benzene rings [91]. 

The other examples of electrochemically driven ring motions in [2]catenanes are from the class of metal complexed catenanes (i.e., catenates) that have been synthesized and studied in our groups. These compounds, the synthesis of which relies on the ability of copper( I) to gather the bidentate phenanthroline ligand around its tetrahedral coordination sphere, are produced in remarkable yield [9, 28, 57f]. The principle of operation is essentially based on the different stereoelectronic requirements of copper(I) and copper(II). Whereas a coordination number of 4, with a tetrahedral or distorted tetrahedral arrangement is preferred by copper(I),... 

The bidentate phenanthroline derivative L9b (Fig. 5) having a pinane skeleton was found to give a good to excellent % ee 75.6% for acetophenone, better than the phenathroHne-oxazoHne L9a as a tridentate Hgand [28]. The tetraden-tate bis(oxazolinyl)-bipyridine Bipymox (LIO) exhibited 90% ee in its RhClj complex [29]. The absolute configuration, S, of the product alcohols was obtained in the same way as in the case of Pybox L8. 

Parameters for the 1,10-phenanthroline complexes, Fe(phen)2X2, with X == Cl", Br", I , NCS , NCSe", Ns" are listed in Table 6.5. The local symmetry is lower than in the Fe(py)4X2 complexes because of the bidentate phenanthroline group, and this results in a larger Fe + quadrupole splitting and smaller magnetic moment. Of particular interest are Fe(phen)2(NCS)2... 

In the presence of the bidentate phenanthroline ligand, the palladacycle is rather stable and does not undergo ring contraction and expansion under the mild conditions reported. 

Schematic representation of [Ru(phen)3] (4.4) showing Ti-stacking interactions between bidentate phenanthroline ligands, giving rise to dimers in solution.

The pyridine ligand in the products shown in Scheme 126 is labile and can be readily replaced by bidentate ligands such as 1,10-phenanthroline (phen) or l,2-bis(diphenylphosphino)ethane (dppe). Scheme 127 illustrates the reaction with phen. ... 

Pyridine-based N-containing ligands have been tested in order to extend the scope of the copper-catalyzed cyclopropanation reaction of olefins. Chelucci et al. [33] have carefully examined and reviewed [34] the efficiency of a number of chiral pyridine derivatives as bidentate Hgands (mainly 2,2 -bipyridines, 2,2 6, 2 -terpyridines, phenanthrolines and aminopyridine) in the copper-catalyzed cyclopropanation of styrene by ethyl diazoacetate. The corresponding copper complexes proved to be only moderately active and enantios-elective (ee up to 32% for a C2-symmetric bipyridine). The same authors prepared other chiral ligands with nitrogen donors such as 2,2 -bipyridines 21, 5,6-dihydro-1,10-phenanthrolines 22, and 1,10-phenanthrolines 23 (see Scheme 14) [35]. 

There are more examples of a second type in which the chirality of the metal center is the result of the coordination of polydentate ligands. The easiest case is that of octahedral complexes with at least two achiral bidentate ligands coordinated to the metal ion. The prototype complex with chirality exclusively at the metal site is the octahedral tris-diimine ruthenium complex [Ru(diimine)3 with diimine = bipyridine or phenanthroline. As shown in Fig. 2 such a complex can exist in two enantiomeric forms named A and A [6,7]. The bidentate ligands are achiral and the stereoisomery results from the hehcal chirality of the coordination and the propeller shape of the complex. The absolute configuration is related to the handness of the hehx formed by the hgands when rotated... 

When the bidentate B is dipyridyl or a substituted o-phenanthroline and M is Cr, only a first-order substitution is observed... 

When M is Mo or W, the substitution reaction follows a two-term rate expression and in addition there is some replacement of the dipyridyl or 1,2-diamino-2-methyl propane but not of o-phenanthroline. The proportion of bidentate replacement to CO replacement is practically independent of the concentration... 

Analogous to the dithiophosphate complexes, cis octahedral complexes are formed with bident-ate ligands like phenanthroline, 2,2 -bipyridine, or tmeda and trans octahedral complexes are formed with monodentate ligands like pyridine and its derivatives. Some examples are mentioned with linear bidentate ligands like 4,4 -bipyridine, which build up ID chains by bridging the [NiL2] molecules.926-933... 

The treatment of gold(III) complexes with the rigid bidentate ligand phen allows the synthesis of pseudo-pentacoordinate gold(III) derivatives. This is the case of [Au(dmp)(phen)PPh3](BF4)2 (288) (dmp = 2-(dimethylaminomethyl)phenyl)1699 or [AuCl(C4Ph4)(phen)].16 2 The donor atoms of the phenanthroline ligand occupy one equatorial and the axial position of a square pyramid with distances 2.154(8)A and 2.627(10)A in (288). 

Pyridyl donors are common and feature in later sections as part of many multidentate ligands, such as macrocycles. Functionalized pyridyl donors will also be discussed and Section 6.8.4.7 provides examples of the bidentate bipyridyl and phenanthroline complexes. 

The presence of zinc with bidentate nitrogen donor ligands in the formation of novel composite materials by hydrothermal reactions has been studied. A zinc-containing one-dimensional material, [Zn(phenanthroline)Mo04] was isolated from molybdate, and from vanadium oxide in the presence of zinc 2,2 -bipyridine [Zn(2,2,-bipyridine)2V40i2] was obtained.212,213... 

The classic low spin [FeN6]2+ systems are those derived from the bidentate diimines 2,2/-bipyridine 1 (bpy) and 1,10-phenanthroline 2 (phen) and the tridentate terimine 2,2/ 6/,2//-terpyridine 3 (trpy). 

Of interest to note is that in previous studies, the kinetics of the substitution reactions with bidentate ligands as shown in Eqs. (34) and (35) have been reported, with Pic = pyridine-2-carboxylate (83) and phen = 1,10-phenanthroline (84)... 

In the presence of the bidentate ligands, 2,2-bipyridyl and 1,10-phenanthroline, phenylethynyltrifluorosilane 842 is in equilibrium with the two possible isomers of the hexacoordinated 1 1 complexes 845 and 846, and 847 and 848, respectively. These have been also investigated by X-ray crystallography (Figure 6).833... 

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