Modification of coordination networks through a photoinduced charge transfer process

Abstract

A photoinduced charge transfer process within the framework of a coordination network leads to an irreversible process that facilitates writing on crystals.

Photochemistry of framework-supported M(diimine)(CO) 3 X complexes in three-dimensional lithium carboxylate metal–organic frameworks: monitoring the effect of framework cations

“…We have investigated the effect of changing the framework-propagating metal cation from transition metals used in previous studies, Mn(II) [18,19] or Cu(II) [20], to an alkali metal, in this case Li(I). The overall framework structure of the MOF, for either ReLi or MnLi, remains highly similar to that observed for the Mn(II)-containing analogues MnMn or ReMn [18,19], despite replacing a single di-cation, Mn(II), with two mono-cations.…”

“…Given the rapid CO recombination observed for the MnMn MOF, we decided to explore the possible effect of modifying the structure and properties of the MOF through changing the framework-propagating cation from a di-positive, potentially redox-active transition metal cation (Mn(II) [18] or Cu(II) [20]) to a mono-positive, redox-inert cation; in our case Li(I) cations. In addition to modifying the nature of the interaction between the carboxylate groups and the framework-propagating cation, two mono-positive cations are required for charge balance, in contrast to a single cation in the case of Mn(II) or Cu(II), potentially leading to structural variations of the framework.…”

“…Our strategy has exploited a divergent multi-functional dicarboxylate ligand which is also capable of binding a supported metal complex-in our studies 2,2 -bipyridine-5,5 -dicarboxylate (1). This approach has been successfully demonstrated by employing M(1)(CO) 3 X (M = Re, Mn; X = Cl, Br) as a ligand in the construction of MOFs, with the carboxylate donors of the 2,2 -bipyridine-5,5 -dicarboxylate ligand binding either Mn(II) [18,19] or Cu(II) [20]. Thus, the M(diimine)(CO) 3 X unit is supported by the extended framework while not being involved in the propagation of the MOF structure.…”

“…Upon replacing the Mn(II) metal cation nodes of the MOF with the potentially redox-active Cu(II), it is possible to make [{Cu(DMF)(H 2 O)[(1)Re(CO) 3 Cl]}•DMF] ∞ ReCu (figure 1b) [20], which has a different overall topology from both ReMn and MnMn. Photo-irradiation of this complex results in an irreversible photo-induced charge transfer process.…”

“…A variety of different photoactive components have been targeted, including systems with photoactive ligands [13,14] but also systems where photoactive moieties such as [Ru(bipy) 3 ] 2+ [15] and, more importantly for this particular study, M(CO) 3 X(diimine) (M = Re, Mn) groups have been investigated [16][17][18][19][20]. Indeed, both Re(CO) 3 X(diimine) [16] and Mn(CO) 3 X(diimine) [17] have been employed for the photocatalytic reduction of CO 2 .…”