Diphosphine‐bridged dicopper(I) acetate complexes [Cu2(μ‐dppm)2(μ‐OAc)]X ( 2X; X− = normalB normalF 4 − , normalP normalF 6 − ) and [Cu2(μ‐dppm)2(μ‐OAc)(MeCN)]X ( 4X) were prepared and the structures of 2(PF6 ) and 4(PF6 ) determined by X‐ray crystallography. The ground‐state geometries of [Cu2(μ‐dppm)2(μ‐OAc)]+ and [Cu2(μ‐dppm)2(μ‐OAc)(L)]+ (L = py, MeCN, THF, acetone, MeOH) were also obtained using density functional theory (DFT). The increased Cu–Cu distances found experimentally and theoretically by comparing the structures of cation [Cu2(μ‐dppm)2(μ‐OAc)]+ and its derivatives [Cu2(μ‐dppm)2(μ‐OAc)(L)]+ reflect the binding of various sigma donors (L). When using [Cu2(μ‐dppm)2(μ‐OAc)]+ as a structure sensor, the electron‐donating strength of a sigma donor can be quantitatively expressed as a DFT‐calculated Cu–Cu distance with the relative strength in the order py > MeCN > THF > acetone > MeOH, as determined.

Currently, main-group metal cations are totally neglected as the structure-building blocks for the self-assembly of supramolecular coordination metallocages due to the lack of directional bonding. However, here we show that a common Arrhenius acid-base neutralization allows the alkaline-earth metal cations to act as charged binders, easily connecting two or more highly directional anionic transition-metal-based metalloligands to coordination polymers. With a metal salt such as K(+) PF6 (-) added during the neutralization, the main-group metal-connected skeleton can be templated by the largest yet reported ionic-aggregate anion, K2 (PF6 )3 (-) , formed from KPF6 in solution, into molecular metallocages, encapsulating the ion. Crystal-structure details, DFT-calculation results, and controlled-release behavior support the presence of K2 (PF6 )3 (-) as a guest in the cage. Upon removal of PF6 (-) ions, the cage stays intact. Other ions like BF4 (-) can be put back in.

The stable tribridged dicopper(I) carboxylate complexes [Cu2(μ‐dppm)2(μ‐O2CR)]BF4 (RCO2 − = formate (OFc−), m1; acetate (OAc−), m2; benzoate (OBAc−), m3; o‐toluate (O2TAc−), m4; p‐toluate (O4TAc−), m5; 4‐phenylbutyrate (O4PBAc−), m6; 2‐nitrobenzoate (O2NBAc−), m7), abbreviated as MM, and neutral dipyridyl compounds (NN; NN = 4,4′‐bipyridine (bpy), 1,2‐bis(4‐pyridyl)ethane (bpa), trans‐1,2‐bis(4‐pyridyl)ethylene (bpe), 4,4′‐trimethylenedipyridine (tmp)) can form dynamic equilibria in CH2Cl2. From the equilibrium mixtures containing MM and NN with MM/NN = 1:1, nine 2:1 oligomers ([(m1)2(μ‐bpy)](BF4)2 (o1a(BF4)2), [(m3)2(μ‐bpe)](BF4)2 (o3c(BF4)2), [(m3)2(μ‐tmp)](BF4)2 (o3d(BF4)2), [(m4)2(μ‐bpe)](BF4)2 (o4c(BF4)2), [(m5)2(μ‐bpy)](BF4)2 (o5a(BF4)2), [(m5)2(μ‐tmp)](BF4)2 (o5d(BF4)2), [(m6)2(μ‐bpa)](BF4)2 (o6b(BF4)2), [(m7)2(μ‐bpy)](BF4)2 (o7a(BF4)2), [(m7)2(μ‐bpa)](BF4)2 (o7b(BF4)2)), one 2:3 oligomer ([{(m2)(bpy)}2(μ‐bpy)](BF4)2 (o2a(BF4)2)), and five 1:1 polymers ([(m2)(μ‐bpe)] n (BF4 ) n (p2c(BF4 ) n ), [(m2)(μ‐tmp)] n (BF4 ) n (p2d(BF4 ) n ), [(m3)(μ‐bpy)] n (BF4 ) n (p3a(BF4 ) n ), [(m3)(μ‐tmp)] n (BF4 ) n (p3d(BF4 ) n ), [(m7)(μ‐tmp)] n (BF4 ) n (p7d(BF4 ) n )) were obtained as single crystals, and their structures were determined by X‐ray crystallography. Both experimental and theoretical results support the presence of two oligomeric species, [{Cu2(μ‐dppm)2(μ‐O2CR)}2(μ‐NN)]2+ and [{Cu2(μ‐dppm)2(μ‐O2CR)(NN)}2(μ‐NN)]2+), in dynamic equilibrium. The oligomers (such as o3d(BF4)2) can serve as seeds to induce the formation of soluble coordination polymers as crystals (such as p3d(BF4)n).

The bridged tetracopper(I) complex [{Cu2(μ‐dppm)2}2(μ‐(1,3‐O2CC6H4 (CO2 )2)](BF4 )2 (2(BF4 )2) was prepared. This complex and the neutral dipyridyl compounds (NN; NN = 4,4′‐bipyridine (bpy), 1,2‐bis(4‐pyridyl)ethane (bpa), 4,4′‐trimethylenedipyridine (tmp)) can form dynamic equilibria in CH2Cl2 . From the equilibrium mixtures containing 2(BF4 )2 and NN with 2(BF4 )2/NN = 1:1, different supramolecular compounds were obtained as single crystals, and their structure were determined by X‐ray crystallography. The flexibility of NN is found to be important in determining the outcome of the reactions with a rigid bpy, leading to the formation of the coordination polymer [{Cu2(μ‐dppm)2}2(μ‐1,3‐C6H4 (CO2 )2)(μ‐bpy)] n (BF4 )2n (3(BF4 )2n ), whereas with flexible bpa and tmp direct the formation of the metalacages [{Cu2(μ‐dppm)2}2(μ‐1,3‐C6H4 (CO2 )2)(μ‐NN)](BF4 )2 (NN = bpa, 4(BF4 )2; tmp, 5(BF4 )2), respectively, as supported by density functional theory (DFT) calculation results.

The organic salts 1‐(2‐pyridylmethyl)‐3‐alkylbenzimidazolium halide (pm‐RbH+X−) and 1‐(2‐pyridylmethyl)‐3‐alkylimidazolium halide (pm‐R′iH+X′−) were prepared (where R = 4‐, 3‐, 2‐fluorobenzyl (4f, 3f, and 2f, respectively), 4‐, 3‐, 2‐chlorobenzyl (4c, 3c, and 2c, respectively); 4‐methoxybenzyl (4mo); 2,3,4,5,6‐pentafluorobenzyl (f5); benzyl (b); and methyl (m)); X = Cl and Br; R′ = benzyl (b) and methyl (m); and X′ = Cl and I. From these salts, heteroleptic Ir(III) complexes containing one N‐heterocyclic carbene (NHC) ligand [Ir(κ2‐ppy)2(κ2‐(pm‐Rb))]PF6 (R = 4f, 1(PF6); 3f, 2(PF6); 2f, 3(PF6); f5b, 4(PF6); 4c, 5(PF6); 3c, 6(PF6); 2c, 7(PF6); 4mo, 8(PF6); b, 9(PF6); m, 10(PF6)) and [Ir(κ2‐ppy)2(κ2‐(pm‐R′i))]PF6 (R = b, 11(PF6); m, 12(PF6)), were synthesized, and the crystal structures of 1(PF6), 2(PF6), 3(PF6), 5(PF6), 6(PF6), 7(PF6), 9(PF6), 10(PF6), and 12(PF6) were determined by X‐ray diffraction. The neutral NHC ligands 1‐(2‐pyridylmethyl)‐3‐alkylbenzimidazolin‐2‐ylidene (pm‐Rb) and 1‐(2‐pyridylmethyl)‐3‐alkylimidazolin‐2‐ylidene (pm‐R′i) of all cations were found to be involved in the intermolecular π−π stacking interactions with the surrounding cations in the solid state, thereby probably influencing the photophysical behavior in the solid state and in solution. The absorption and emission properties of all the complexes show only small variations.