Two diene molecules were shown to undergo photopolymerization reactions in their metal–organic gels and xerogels, while their respective crystalline CPs are photostable. These reactions reveal the advantages of the gels and xerogels compared to their crystalline counterparts and also the utility of Ag⋯Ag interactions in the gels to promote topochemical polymerizations.
![Graphical abstract: Solid or gel? Which one works better for [2 + 2] photochemical polymerization in pyridine appended flexible phenylene 1, 4-bis-olefins by Ag(i) templation?](http://hg.y866.cn/compound/lib/scimg/usr/1/C9DT04304G.jpg)
