ABSTRACT
The reaction of potassium (aza-15-crown-5)dithiocarbamate (KO4NCS2) and (Me2S)AuCl gave the dinuclear complex [Au(O4NCS2)]2, which underwent structural transformation upon heating to rearrange into the hexanuclear complex [Au(O4NCS2)]6. Under similar reaction conditions, KO4NCS2 reacted with AgNO3 or [Cu(CH3CN)4]ClO4 to give the 1-D coordination polymer [Ag(O4NCS2)]n (1) and the tetranuclear complex [Cu(O4NCS2)]4 (2), respectively. It is noted that upon heating a similar structural transformation process occurs from tetranuclear complex 2 to the octanuclear complex [Cu(O4NCS2)]8 (2'), connected by a weak Cuâ¯S contact of 2.846 Å, and it has been isolated and corroborated by powder and single-crystal X-ray diffraction studies as well. Moreover, a variety of MO4NCS2 salts (M = Li+, Na+, K+ and Rb+) were used to react with AgNO3 to construct a series of coordination architectures: [LiAg(O4NCS2)2(µ-H2O)0.5]2 (3), {Na[Ag(O4NCS2)2]}n (4), {K[Ag(O4NCS2)2]}n (5) and {Rb[Ag(O4NCS2)2]}n (6). The smallest Li+ ion only coordinates with four oxygen atoms from the same azacrown ether ring and one H2O molecule, leading to a 1-D hydrogen-bonded chain with another azacrown ether ring for complex 3. The larger Na+ ion coordinates with seven oxygen atoms from two different crown ether rings, leading to a 1-D chain for complex 4. However, the largest K+ and Rb+ ions constitute a 1-D framework, except that each metal ion coordinates with eight oxygen atoms from two different crown ether rings, featuring a 1-D helical chain for complexes 5 and 6. Hence, the different sizes of alkaline metal ions exert a dramatic effect on the structural motifs of complexes 3-6. Remarkably, the dithiocarbamate moieties adopt µ2-bridging ([Au(O4NCS2)]2 and [Au(O4NCS2)]6), µ3- and µ4-bridging (1-2) and chelate forms (3-6) in the structural backbones.
Subject(s)
Coordination Complexes , Crown Ethers , Coordination Complexes/chemistry , Ions , OxygenABSTRACT
The reaction of AuCl(SMe2) with equimolar NaO5NCS2 [O5NCS2 = (aza-18-crown-6)dithiocarbamate] in CH3CN gave [Au2(O5NCS2)2]·2CH3CN (2·2CH3CN), where six other 2·solvates (solvates = 2DMF, 2DMSO, 2THF, 2acetone, 1.5toluene, and 1.5anisole) can be successfully isolated from different crystal-growing processes (i.e., ether diffusion, layer method, or evaporation in air) by dissolving the dry powder samples of 2·2CH3CN in the respective solvents, and their crystal structures are all determined by X-ray diffraction as well. It is noted that there are different intermolecular Au(I)···Au(I) contacts in combination with various luminescences for 2·solvates and indeed there is a close relationship between intermolecular Au(I)···Au(I) contacts [i.e., 2.8254(7)-2.9420(5) Å] and luminescence energies (i.e., 554-604 nm), including three examples of 2·2CH3CN, 2·0.5m-xylene, and 2·tert-butylbenzene·H2O reported in our previous work. In 2·solvates, the toluene and tert-butylbenzene solvates have the shortest [2.8254(7)-2.8289(7) Å] and longest [2.9420(5) Å] intermolecular Au(I)···Au(I) contacts, respectively, and consequently they show the respective lowest (604 nm) and highest (554 nm) luminescence energies. Indeed, 2·solvates exhibit different types of time-dependent luminescence upon solvate loss in air. Furthermore, B3LYP/LanL2DZ calculation results can help to clarify the relationship between intermolecular Au(I)···Au(I) contacts and luminescence energies for 2·solvates.