Divergent Terpyridine‐Based Coordination for the Construction of Photoactive Supramolecular Structures

Abstract

Exploring new materials to manipulate luminescent radiation and investigate the interaction of light and matter is one of the most compelling prospects of our century. Supramolecular chemistry has unraveled the opportunity to synergistically combine the chemical and optoelectronic properties of the most diverse classes of compounds. Among these, terpyridines have acted as pivotal ligand units that enable selfassembly of multicomponent chromophoric systems. In this review we therefore elucidate the metal-coordinating ability of [a]

Directing 2D-Coordination Networks: Combined Effects of a Conformationally Flexible 3,2′:6′,3″-Terpyridine and Chain Length Variation in 4′-(4-n-Alkyloxyphenyl) Substituents

“…In each compound, the cobalt atom acts as a four-connecting node, and adjacent metal centers are bridged by 3,2 :6 ,3"-tpy units to produce (4,4) nets. This is reminiscent of the coordination networks assembled from Co(NCS) 2 and 4,2 :6 ,4"-tpy ligands functionalized with 4 -tert-butyl, 4 -(4-methoxyphenyl), 4 -(4-ethoxyphenyl) and 4 -(4-n-propoxyphenyl) substituents [23].…”

“…In contrast, in [Co 2 (5) 4 (NCS) 4 ] n and [Co(6) 2 (NCS) 2 ] n , the 2D-networks pack in an ABAB... fashion (Figure 8), allowing the n-pentyloxy and n-hexyloxy to penetrate into the cavities in an adjacent sheet. A significant point is that in the case of the reaction of Co(NCS) 2 with ligand 1, there is competition between the formation of a (4,4) [19]) and a 1D-coordination polymer [Co(1)(NCS) 2 (MeOH) 2 ] n , with the 1D-coordination polymer being the dominant product [19]. Powder XRD confirmed that this is not the case for the coordination polymers formed with ligands 5 and 6, and the single-crystal structures of [Co 2 (5) [19].…”

“…Terpyridine (tpy) possesses 48 possible isomers, of which 2,2 :6 ,2"-tpy is the most commonly encountered [1][2][3][4][5]. Coordination to a metal usually involves a conformational change from the limiting trans,trans-form found for the free ligand to the limiting cis,cis-conformer as two chelate rings are formed (Scheme 1a).…”

“…The 3,2 :6 ,3"-tpy and 4,2 :6 ,4"-tpy metal-binding domains differ in their degrees of conformational flexibility [10]. We recently demonstrated that in a series of 1D-coordination polymers [Cu 2 (µ-OAc) 4 (L)] n in which L is a 4 -(4-n-alkyloxyphenyl)-substituted 3,2 :6 ,3"-tpy ligand, conformational changes of the 3,2 :6 ,3"-tpy domain associated with an increase in the length of the n-alkyloxy substituent results in significant changes in the conformation and packing of the coordination polymer chains [11]. The use of 4,2 :6 ,4"-tpy ligands, often functionalized in the 4 -position, as building blocks in coordination polymers and networks has gained in popularity over the last decade [12,13].…”

Switching the Conformation of 3,2′:6′,3″-tpy Domains in 4′-(4-n-Alkyloxyphenyl)-3,2′:6′,3″-Terpyridines

“…The coordination chemistry of 2,2′:6′,2″-terpyridine (tpy) is well established, and is dominated by tpy acting as a bis-chelating ligand [ 1 , 2 , 3 , 4 , 5 ]. The terpyridine isomers 3,2′:6′,3″-tpy and 4,2′:6′,4″-tpy ( Scheme 1 a) are growing in popularity as building blocks in coordination polymers owing to the vectorial properties of the outer pyridine N -donors, and the fact that the central pyridine ring is coordinatively innocent [ 6 , 7 , 8 ].…”