Synthesis of 4′-Substituted-2,2′:6′,2′′-Terpyridines

Abstract

The terdentate ligand 2,2′:6′,2′′-terpyridine (tpy) has increasingly become one of the most popular ligands in coordination chemistry. A variety of substituents are utilised to tailor the properties of its metal complexes. 2,2′:6′,2′′-Terpyridine was reacted with almost all transition metals to form complexes. Among a series of tpy ligand derivatives, those containing substituents at the C(4′) position are of especial interest. Metal-bonded tpy ligands with spacers at C(4′) provide a means of directionality, and thus a means of linear communication, it means that electronic communication can occur along the coordination axis. In addition, the insertion of a single substituent at the C(4′)-position of the tpy ligand results in no enantiomeric derivatives, as the derivative retains its plane of symmetry. The synthetic strategies used to prepare tpy ligands are reviewed comprehensively.

New 4′‐Functionalized 2,2′:6′,2′′‐Terpyridines for Applications in Macromolecular Chemistry and Nanoscience

“…[14] Herein we present the synthesis of a variety of terpyridines functionalized in the 4Ј-position, by the well-known nucleophilic substitution reaction of alkoxides (alkoxides, formed in situ under the strong basic conditions Ϫ KOH/DMSO Ϫ are, in contrast to the corresponding alcohols, good nucleophiles) with 4Ј-chloro-2,2Ј:6Ј,2ЈЈ-terpyridine, [15] first described by Newkome et al [16] It should be mentioned that the synthesis of such 4Ј-ether-bridge-functionalized terpyridines can also be carried out starting from the precursor of 4Ј-chloro-2,2Ј:6Ј,2ЈЈ-terpyridine, the 2,2Ј:6Ј,2ЈЈ-terpyridin-4Ј(1ЈH)-one, which, in contrast, requires an electrophile as functionalizing reactant. [14,17] Two of the amine-and carboxyfunctionalized terpyridines presented here have already been applied to the construction of dendritic structures [16] or the functionalization of coiled-coil peptide sequences. [18] Furthermore, the alkyl-chain-functionalized terpyridines presented here formed ordered two-dimensional structures on HOPG (Highly Ordered Pyrolytic Graphite), which were investigated by STM.…”

Complexation and C–H bond activation of 2,2′:6′,2″-terpyridyl molecules on triosmium carbonyl clusters: Synthesis and characterization of the double-cluster {Cp3Fe4(CO)4(C5H4-terpyridyl)Os3(μ-H)(CO) } (n= 9, 10)

“…Reaction of Fe 4 tpyH with Os 3 (CO) 10 (NCMe) 2 in hot methylcyclohexane (90 C) afforded the mixed-metal double clusters (m-H)Os 3 (m,h 2 -Fe 4 tpy)(CO) 10 (1; 14%) as a green solid and (m-H) Os 3 (m,h 3 -Fe 4 tpy)(CO) 9 (2; 31%) as a brown solid, after separation by TLC (neutral alumina) and crystallization from CH 2 Cl 2 /n-hexane. By the same reaction and purification methods, FtpyH reacted with Os 3 (CO) 10 (NCMe) 2 to produce yellow crystals of (m-H) Os 3 (m,h 2 -Ftpy)(CO) 10 (3) in 16% yield, together with a red crystalline solid of (m-H)Os 3 (m,h 3 -Ftpy)(CO) 9 (4) in 32% yield.…”

“…The well-known characteristics of TpyH metal complexes are their special redox and photophysical properties [2,3], which can be used to prepare luminescent materials [4e6] and molecular electronics [7,8]. Apart from TpyH itself, a great number of terpyridines bearing different functional groups have been designed to tune the steric, electronic, and photophysical properties of their metal complexes [9,10]. They have also been utilized for catalytic purposes [11,12], polymer syntheses [13,14], and for building supramolecular architectures [15].…”

3-(2,2′:6′,2′′-Terpyridin-4′-yloxy)propyl toluene-4-sulfonate

“…The synthesis of functionalized 2,2 0 ;6 0 ,2 00 -terpyridines was recently reviewed by Fallahpour (2003) as well as Heller & Schubert (2003). 4 0 -Substituted 2,2 0 ;6 0 ,2 00 -terpyridines have received major attention due to their symmetry, which prevents the formation of enantiomers upon complexation.…”