Schlüssel zum Öffnen photolabiler, metallhaltiger Käfige

Abstract

Photolabile metallhaltige Käfige sind Metallkomplexe, die bei Bestrahlung mit Licht geeigneter Wellenlänge eine Veränderung der Koordinationsumgebung erfahren. Dabei kann entweder der verkapselnde Ligand allein oder der gesamte Metallkomplex photoresponsiv sein. Die veränderten Koordinationseigenschaften photoresponsiver Komplexe können mehrere Auswirkungen haben: eine Freisetzung des koordinierten Metallions in seine Umgebung, eine veränderte Reaktivität des Metallzentrums oder die Abspaltung eines reaktiven Moleküls, das zuvor durch Bindung an das Metallzentrum passiviert war. Diese photoaktivierbaren Systeme können von Nutzen sein, um die Bioverfügbarkeit von Metallen oder ihren koordinierenden Liganden für das Studium biologischer Reaktionspfade oder für mögliche therapeutische Zwecke zu manipulieren.

A Bis(dipyridophenazine)(2‐(2‐pyridyl)pyrimidine‐4‐carboxylic acid)ruthenium(II) Complex with Anticancer Action upon Photodeprotection

“…[10] Whilst photochemical control of activity (also referred to as "photocaging/uncaging") has been widely explored with organic drugs, application of this concept to metal coordination complexes has been surprisingly limited. [9,11] Of note, metal complexes were previously used in combination with light to trigger biological activity. [3a, 11, 12] Specific to substitutionally inert Ru II complexes, photoactivation to date has primarily revolved around the studies exploring their capacity to undergo photoinduced ligand exchange/expulsion, DNA binding, DNA cleavage, and cytotoxic effects.…”

A Bis(dipyridophenazine)(2‐(2‐pyridyl)pyrimidine‐4‐carboxylic acid)ruthenium(II) Complex with Anticancer Action upon Photodeprotection

“…Efforts towards this end are currently under investigation. It should be noted, however, that the UV‐A light dosage (2.58 J cm −2 ) used to induce cytotoxicity in C2 is comparable to that frequently employed for other UV‐A activated metal complexes 11. 12d, 18…”

“…Whilst photochemical control of activity (also referred to as “photocaging/uncaging”) has been widely explored with organic drugs, application of this concept to metal coordination complexes has been surprisingly limited 9. 11 Of note, metal complexes were previously used in combination with light to trigger biological activity 3a. 11, 12 Specific to substitutionally inert Ru II complexes, photoactivation to date has primarily revolved around the studies exploring their capacity to undergo photoinduced ligand exchange/expulsion, DNA binding, DNA cleavage, and cytotoxic effects 3a.…”

“…11 Of note, metal complexes were previously used in combination with light to trigger biological activity 3a. 11, 12 Specific to substitutionally inert Ru II complexes, photoactivation to date has primarily revolved around the studies exploring their capacity to undergo photoinduced ligand exchange/expulsion, DNA binding, DNA cleavage, and cytotoxic effects 3a. 4a–c, 13 To the best of our knowledge, this work is the first example of a light‐triggered structurally inert metallo‐prodrug candidate, with no “caged” variants of any substitutionally inert cytotoxic metal complex been previously constructed.…”

Light‐Controlled Release and Uptake of Zinc Ions in Solution by a Photochromic Terthiazole‐Based Ligand

“…[21,22] By offering ac onvenient and non-invasive way to reversiblyp hoto-modulate the concentration of ag iven metal ion in solution, such metal complexes are of interest for ab road range of potential applications, particularly in biology where as trict regulation of the concentration of different metals is crucial for the healthyf unctioning of cells. [23][24][25][26] We have recently reported at erphenylthiazole-based multifunctional photo-switch that combines as alen-like cavity capable of bindingawide range of metal ions and two typeso f photochemical reactions:6 p electrocyclization/cycloreversion of the backbone and excited state intramolecular proton transfer (ESIPT),o ccurring between the hydrogen atom of one of the two hydroxyl groups and the nitrogen atom of the neighboring thiazolyl group (Scheme 1). [27] The ESIPT process confers av ery sensitive fluorescencet ot he open form 1a and the electrocyclization/cycloreversion allows its reversible photomodulation to al arge extent.…”