Recent advances in the synthesis and applications of 2,6-dipyrazolylpyridine derivatives and their complexes

Abstract

Developments in the chemistry of 2,6-di(pyrazol-1-yl)pyridine (1-bpp) and 2,6-di(pyrazol-3-yl)pyridine (3-bpp), their derivatives and their complexes are surveyed, with emphasis on the last eight years. Particular advances include the synthesis of multi-functional spin-crossover switches; the incorporation of emissive f-element podand centres into biomedical sensors; the self-assembly of a variety of functional soft materials and surface structures; and, the use of 3-bpp complexes in catalysis.

Synthesis and selected lanthanide coordination chemistry of new ((1H-pyrazol-1-yl)methyl)pyridine and -pyridine 1-oxide ligands

“…As mentioned in the Introduction, the lanthanide coordination chemistry of numerous derivatives of 1-bpp (A) and 3-bpp (B) ligands has been extensively developed [6][7][8][9]. Based upon single crystal X-ray structure analyses, it is generally found that these bis-(pyrazole)pyridine ligands bind in a tridentate N pyrz N pyrz N pyrd manner on Ln(III)ions.…”

Supramolecular assembly and transfer hydrogenation catalysis with ruthenium(II) complexes of 2,6-di(1H-pyrazol-3-yl)pyridine derivatives

“…The new ligand L Et,H (Scheme 1) was prepared by the usual route for 5',5''-disubstituted 3-bpp derivatives [1,2,26]; that is, by a Claisen condensation of dimethyl 2,6-dipicolinate with 2 equiv butan-2-one, followed by treatment of the resultant bis- (Tables 2 and 3). Notably, the ruthenium coordination sphere in the two structures is different; while 1·MeOH contains coordinated chloride ( Fig.…”

“…Complexes of ligands derived from 2,6-di(pyrazol-3-yl)pyridine Scheme 1) are finding increasing use [1], in fields as diverse as spin-crossover compounds [2,3], dyesensitized solar cells [4], emissive materials [5], metal ion separation [6] and catalysis [7][8][9][10][11][12][13][14][15][16][17].…”

Iron(ii) complexes of 4-sulfanyl-, 4-sulfinyl- and 4-sulfonyl-2,6-dipyrazolylpyridine ligands. A subtle interplay between spin-crossover and crystallographic phase changes

“…[8][9][10] A particular advantage of these complexes is that synthetic routes are available to functionalise [Fe(bpp) 2 ] 2+ centres at every position of their ligand periphery. 11 On one hand, this provides a route to attach functional substituents to [Fe(bpp) 2 ] 2+ centres for the production of multifunctional switchable materials. 12 On the other hand, it also provides a means to attach tether groups to [Fe(bpp) 2 ] 2+ , for use in nanostructures or device applications.…”