Syntheses, structures and photophysical properties of binuclear copper(I) complexes bridged by diphosphine ligands

Aggregation-Induced Emissive Copper(I) Complexes for Living Cell Imaging

“…ORTEP drawings of the cations for Cu-1–Cu-4 are depicted in Figures and . All complexes exhibit binuclear structures, which are similar to those of [Cu 2 (BrbpyBr) 2 (Ph 2 P(CH 2 ) n PPh 2 ) 2 ](ClO 4 ) 2 ( n = 1, 4, 5, and 6) and [Cu 2 (dmp) 2 (dppb) 2 ](PF 6 ) 2 complexes reported by us and others. , The two [Cu(BrphenBr)] + units are bridged by two diphosphine ligands forming 8-membered Cu 2 C 2 P 4 , 14-membered Cu 2 C 8 P 4 , 16-membered Cu 2 C 10 P 4 , and 18-membered Cu 2 C 12 P 4 metallacycles in Cu-1 , Cu-2 , Cu-3 , and Cu-4 , respectively. It is interesting to note that these metallacycles adopt different conformations, and those metallacycles of Cu-1–Cu-3 in the crystals adopt staggered conformations (see Figure S2, Supporting Information), but 18-membered Cu 2 C 12 P 4 metallacycles of Cu-4 adopt both eclipsed and staggered conformations (see Figure ).…”

“…The distortion is mainly induced by the rigid BrphenBr ligand, which restricts the N–Cu–N bite angles to 79.0(3)° for Cu-1 , 79.7(1)° for Cu-2 , 79.4(3)° for Cu-3 , and 80.3(2)° and 79.9(2)° for Cu-4 . The corresponding P–Cu–P angles are 136.2(1)° for Cu-1 , 118.3(1)° for Cu-2 , 125.4(1)° for Cu-3 , and 127.3(1)° and 126.3(1)° for Cu-4 , showing much variation to each other, but they are very similar to those in binuclear [Cu 2 (BrbpyBr) 2 (Ph 2 P(CH 2 ) n PPh 2 ) 2 ](ClO 4 ) 2 complexes and much larger than 91.0(1)° in mononuclear [Cu(BrphenBr)(bdpp)]ClO 4 complex . Such similarity or difference depends on whether the diphosphine ligand adopts a bridging mode or a chelating mode.…”

“…The dihedral angles between the P–Cu–P and the N–Cu–N planes shown in Figure S3 (see Supporting Information) are 89.0(2)° for Cu-1 , 88.4(1)° for Cu-2 , 86.0(2)° for Cu-3 , and 87.2(2)° and 88.3(1)° for Cu-4 , which are a little smaller than 89.6° in mononuclear complex [Cu(BrphenBr)(bdpp)]ClO 4 and similar to 86.2(1)–88.6(2)° in binuclear [Cu 2 (BrbpyBr) 2 (Ph 2 P(CH 2 ) n PPh 2 ) 2 ](ClO 4 ) 2 complexes . Both the larger P–Cu–P angles and the smaller dihedral angles imply that the PPh 2 groups in these binuclear complexes are sterically much closer to the BrphenBr ligands than those in the mononuclear complex [Cu(BrphenBr)(bdpp)]ClO 4 , and this can be seen from Figures and and Figure S4 (see Supporting Information, the space fillings of cations of complexes Cu-1 – Cu-4) . As shown in Figure S4, Supporting Information, all copper(I) centers, together with coordinated N and P atoms, are effectively protected by the phenyl rings, methylene groups of diphosphine ligands, and bromine atoms of BrphenBr in complexes Cu-1 – Cu-4 , implying that complexes Cu-1 – Cu-4 are very stable to air and moisture in the solid state.…”

“…To date, a series of Cu(I) complexes has been applied in OLED, − solar-energy conversion devices, , and chemosensors. − Unfortunately, no example of a phosphorescent Cu(I) complex has been reported in application of luminescent bioimaging due to the instability caused by the oxidization and disproportionation of the Cu(I) ion. In the past decade, the study of phosphorescent Cu(I) complexes has mainly focused on Cu(I)–diimine complexes, especially the mixed-ligand Cu(I)–diimine–diphosphine [Cu(diimine)(PP)] + and [Cu 2 (diimine) 2 (PP) 2 ] 2+ (PP = diphosphine ligand) complexes due to the relatively abundant resource, less expensive noble-metal-free characteristics, controllable electronic and stereochemical characteristics of ligands, and good luminescent performance. − A recent report showed some Cu(I)–diimine–diphosphine complexes can be used as photosensitizers for photocatalytic reduction of protons from water at room temperature . In particular, the binuclear complex [Cu 2 (dmp) 2 (dppb) 2 ](PF 6 ) 2 (dmp = 2,9-dimethyl-1,10-phenanthroline, dppb = 1,4-bis(diphenylphosphino)butane) has been proved to be a stronger emitter with a higher quantum yield and a longer lifetime than the corresponding chelating mononuclear [Cu(dmp)(dppe)]PF 6 (dppe = 1,2-bis(diphenylphosphino)ethane) and [Cu(dmp)(dppp)]PF 6 (dppp = 1,3-bis(diphenylphosphino)propane) complexes (see Figure S1, Supporting Information).…”

Copper(I) Complexes of a Flexible Bis-phospholane Ligand: Route to Paddle-Wheel- and Box-Type Macrocycles

“…Copper­(I) has also been employed as a metal center in the preparation of mixed-ligand coordination oligomers and polymers with bis-phosphine and diisocyanide ligands . Heteroleptic dinuclear copper­(I) complexes bearing flexible bis­(diphenylphosphine) and chelating N,N ligands (bipyridine, phenanthroline, pyridyl-tetrazole) have also been reported and their photophysical properties investigated. , However, the phospholane homologues (flexible bis-phospholane ligands) are virtually unexplored. Recently, we reported the facile synthesis of gold­(I) and silver­(I) frame-like macrocycles using such ligands.…”