TY - JOUR
T1 - Solid-State Luminescence of Au-Cu-Alkynyl Complexes Induced by Metallophilicity-Driven Aggregation
AU - Koshevoy, Igor O.
AU - Chang, Yuh-Chia
AU - Karttunen, Antti J.
AU - Shakirova, Julia R.
AU - Janis, Janne
AU - Haukka, Matti
AU - Pakkanen, Tapani
AU - Chou, Pi-Tai
PY - 2013/4
Y1 - 2013/4
N2 - A new series of homoleptic alkynyl complexes, [{Au2Cu2(C2R)4}n] (R=C3H7O (1), C6H11O (2), C9H19O (3), C13H11O (4)), were obtained from Au(SC4H8)Cl, Cu(NCMe)4PF6, and the corresponding alkyne in the presence of a base (NEt3). Complexes 14 aggregate upon crystallization into polymeric chains through extensive metallophilic interactions. The cluster that contains fluorenolyl functionalities, C13H9O (5), crystallizes in its molecular form as a disolvate, [Au2Cu2(C2C13H9O)4]2THF. The substitution of weakly bound THF molecules with pyridine molecules leads to the complex [Au2Cu2(C2C13H9O)4]2py (6), thus giving two polymorphs in the solid state. Such structural diversity is established through metal-chain and hydrogen-bond formation, which depends on the stereochemical characteristics of the organic ligands. More interestingly, this solid-state structural arrangement affords good emission properties, such as intensity and spectroscopic profile, which are otherwise very weakly emissive in solution. Metallophilic aggregation of the {Au2Cu2} cluster units, as observed in the crystals, results in dramatic enhancement of the room-temperature phosphorescence, thereby reaching a maximum quantum efficiency of 95% (4). A theoretical approach further indicates a synergistic effect of the array of the metal chain upon aggregation, which greatly enhances the spin-orbit coupling and, hence, the phosphorescence, thereby opening up a new direction in the field of aggregate-enhanced emission.
AB - A new series of homoleptic alkynyl complexes, [{Au2Cu2(C2R)4}n] (R=C3H7O (1), C6H11O (2), C9H19O (3), C13H11O (4)), were obtained from Au(SC4H8)Cl, Cu(NCMe)4PF6, and the corresponding alkyne in the presence of a base (NEt3). Complexes 14 aggregate upon crystallization into polymeric chains through extensive metallophilic interactions. The cluster that contains fluorenolyl functionalities, C13H9O (5), crystallizes in its molecular form as a disolvate, [Au2Cu2(C2C13H9O)4]2THF. The substitution of weakly bound THF molecules with pyridine molecules leads to the complex [Au2Cu2(C2C13H9O)4]2py (6), thus giving two polymorphs in the solid state. Such structural diversity is established through metal-chain and hydrogen-bond formation, which depends on the stereochemical characteristics of the organic ligands. More interestingly, this solid-state structural arrangement affords good emission properties, such as intensity and spectroscopic profile, which are otherwise very weakly emissive in solution. Metallophilic aggregation of the {Au2Cu2} cluster units, as observed in the crystals, results in dramatic enhancement of the room-temperature phosphorescence, thereby reaching a maximum quantum efficiency of 95% (4). A theoretical approach further indicates a synergistic effect of the array of the metal chain upon aggregation, which greatly enhances the spin-orbit coupling and, hence, the phosphorescence, thereby opening up a new direction in the field of aggregate-enhanced emission.
KW - aggregation
KW - copper
KW - gold
KW - luminescence
KW - polymers
KW - LIGHT-EMITTING-DIODES
KW - CYCLOMETALATED ALKYNYLGOLD(III) COMPLEXES
KW - APPROXIMATE COULOMB POTENTIALS
KW - DENSITY-FUNCTIONAL METHODS
KW - TRIPLET EXCITED-STATES
KW - AUXILIARY BASIS-SETS
KW - INDUCED EMISSION
KW - I COMPLEXES
KW - AUROPHILIC INTERACTIONS
KW - COPPER(I) COMPLEXES
U2 - 10.1002/chem.201204611
DO - 10.1002/chem.201204611
M3 - Article
SN - 0947-6539
VL - 19
SP - 5104
EP - 5112
JO - CHEMISTRY: A EUROPEAN JOURNAL
JF - CHEMISTRY: A EUROPEAN JOURNAL
IS - 16
ER -