摘要:
One-pot reaction of [CpCo(CO)(2)], elemental sulfur with some heterocycle-substituted alkynes (R-C C-HET) produced [CpCo(dithiolene)] complexes with (PyOBn)-Py-2 (2), with both (PyOBn)-Py-2 and 2-hydroxy-2-propyl groups (C(OH)Me-2) (5), both Py-2 and C(OH)Me-2 (8), both Py-4 and C(OH)Me-2 (11), and with Py-4 substituent (13). A deprotection of benzyl group (Bn) from 2 with trimethylsilyl iodide formed [CpCo(dithiolene)] with 2-pyridonyl substituent (3). Heating reaction of 8 without any base resulted in the C(OH)Me-2 group elimination to form the 2-pyridylethylenedithiolate complex (9), but 11 underwent only dehydration at the C(OH)Me-2 under heating. While the preparation of 5, the benzyl free complex (6) was obtained as a main product. 6 has a dithiolene-fused tricyclic pyridone skeleton. The structures of 3, 5, 6, 8, and 11 were determined by X-ray diffraction studies. Intramolecular OH center dot center dot center dot N(Py-2) hydrogen bondings are found in 5 and 8, and an intermolecular OH center dot center dot center dot N(Py-4) one is found in 11 at solid state. In the 2-pyridonyl complex 3, intermolecular NH center dot center dot center dot O and CH(dithiolene)center dot center dot center dot O hydrogen bondings are observed. 8 showed an intermolecular Cp center dot center dot center dot Cp face-to-face interaction. The tricyclic complex 6 exhibited lower energy electronic absorption (lambda(max) = 668 nm) compared with the others (lambda(max) = 562-614 nm), due to an extended pi-conjugation of aromatic cobaltadithiolene ring. (C) 2009 Elsevier B.V. All rights reserved.