Bidentate nitrogen

Organometallic compounds apart, oxidation states below - -2 are best represented by complexes with tris-bidentate nitrogen-donor ligands such as 2,2 -bipyridyl. Reduction by LiAlH4 in thf yields tris(bipyridyl) complexes in which the formal oxidation state of vanadium is -1-2 to —1. Magnetic moments are compatible with low-spin configurations of the metal but. 

With Hg2 bidentate nitrogen ligands form complexes that have chain structures. For example, 1,4-diazine III forms a complex [Hg2(C4H4N2XN03)2] (IV) that has Hg—Hg units joined in infinite chains, with the [N03] groups between the chains . ... 

Figure 1.27 Structure of the anionic, bidentate nitrogen ligands [hpp] and [tbo] ...

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... 

Complexes of zinc dialkyldithiocarbamates with bidentate nitrogen ligands such as 1,10-phen-anthroline have been structurally characterized.563 The related complexes (4,4 -bipyridyl)... 

Interaction of iV-pentafluorophenylcarbonimidoyl dichloride with benzonitrile and aluminium trichloride leads to l-pentafluorophenyl-4,6-diphenyl-13 -triazin-2-one along with urea derivatives . Reaction of perfluoro-5-azanon-4-ene with a range of bidentate nitrogen nucleophiles (urea, substituted amidine hydrochlorides and guanidine), in the presence of triethylamine or potassium hydroxide, effectively provides fluorinated 1,3,5-triazines 16-19 <00JFC(103)105>. 

Nakash et al. have studied the reaction of phenylethynyltrifluorosilane 842 with mono- and bidentate nitrogen bases in solution using a combination of H, 13C, 1SN, 19F, and 29Si NMR spectroscopy, which gives rise to formation of... 

A great nnmber of chiral bidentate nitrogen and oxygen ligands, which served well with other cations than lithinm, are known . Only very limited success was achieved with organolithium compounds in the classical examples of addition reactions onto aldehydes 335-337... 

Early NOE studies on cationic Pd(ii) allyl complexes used reporter ligands [97, 98], i. e. simple bidentate nitrogen ligands, such as bipy or phenanthroline, whose... 

Whereas the simple bidentate nitrogen ligands proved to be rather limited, the frequent occurrence of a set of four P-phenyl or alkyl substituents, e. g., in coordinated Binap, MeO-Biphep, Josiphos or Duphos (shown, from left to right in Scheme 1.4), offered many more reporters . In this way, one can develop a more detailed NOE picture of how the complexed substrate interacts with the chiral pocket offered by these auxiliaries. From these NOE studies [97, 98] it can be shown that the atropisomeric bidentate ligands Binap and MeO-Biphep tend to have fairly classical axial and equatorial P-phenyl substituents. 

The stoichiometry and IR spectrum of [CufSb eHj ] 3(N03)] are therefore consistent with a four-coordinate derivative containing unidentate nitrate. This complex has been shown to be useful for the preparation of complexes of the type [Cu(N,N)2] N03 (7V,jV-bidentate nitrogen ligand such as 1,10-phenan-throline).19... 

The synthesis of syndiotactic alternating styrene/CO co-polymers with bidentate nitrogen-ligated Pd complexes has already been reported, but thus far, there have never been any reports of a-olefm and CO-based congeners. Syndioselective alternating co-polymerization is believed to proceed via a chain-end control mechanism. 

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