Montes-Ayala Josefina, Escartín-Guzmán Concepción, Castillo-Blum Silvia E, Rodríguez-Hernández Edgar O, Bernès Sylvain, Rosales-Hoz Maria Jesús, Barba-Behrens Noráh
Departamento de Química Inorgánica, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, Coyoacán, México, D.F. 04510, Mexico.
J Inorg Biochem. 2005 Aug;99(8):1676-84. doi: 10.1016/j.jinorgbio.2005.05.010.
The synthesis and characterisation of the following compounds derived from the biological relevant compound ethyl 5-methyl-4-imidazolecarboxylate (emizco) (1): [Cu(emizco)Cl2] (2), [Cu(emizco)2Cl2] (3), [Cu(emizco)2Br2] (4), Cu(emizco)2(H2O)22 (5) and Cu(emizco)42 (6), is presented. These compounds were characterised by IR and UV spectroscopic techniques, in addition the crystal structures of compounds 1-5 were determined. For complexes 2-5, emizco is coordinated as a bidentate ligand, through the oxygen atom of the carboxylate moiety and the nitrogen atom of the imidazolic ring. Different geometries are stabilised: compound 2 includes a pentacoordinated square pyramidal metal centre, while 3-5 are derived from octahedral geometry. Halide compounds 3 and 4 show a cis-octahedral arrangement, which is not very common on [CuN2O2X2] systems, while 5 stabilises the trans-octahedral isomer. Compound 6 displays a square planar geometry. Finally, hydrolysis of emizco to its corresponding carboxylic acid (mizco), allowed the preparation of another square planar complex 7, identified as [Cu(mizco)2] 0.5H2O. Solution studies of these compounds indicate that emizco is not substituted from the coordination sphere, remaining as a bidentate ligand. Halides are substituted by water molecules, changing from cis octahedral to the trans-[Cu(emizco)2(H2O)2]2+ isomer.
本文介绍了以下源自生物相关化合物5-甲基-4-咪唑甲酸乙酯(emizco)(1)的化合物的合成与表征:[Cu(emizco)Cl2](2)、[Cu(emizco)2Cl2](3)、[Cu(emizco)2Br2](4)、Cu(emizco)2(H2O)22(5)和Cu(emizco)42(6)。这些化合物通过红外光谱和紫外光谱技术进行了表征,此外还测定了化合物1-5的晶体结构。对于配合物2-5,emizco作为双齿配体配位,通过羧酸根部分的氧原子和咪唑环的氮原子。不同的几何构型得以稳定:化合物2包含一个五配位的四方锥金属中心,而3-5则源自八面体几何构型。卤化物化合物3和4呈现顺式八面体排列,这在[CuN2O2X2]体系中并不常见,而5则稳定了反式八面体异构体。化合物6呈现平面正方形几何构型。最后,emizco水解为其相应的羧酸(mizco),从而制备了另一种平面正方形配合物7,鉴定为[Cu(mizco)2]·0.5H2O。这些化合物的溶液研究表明,emizco不会从配位球中被取代,仍作为双齿配体存在。卤化物被水分子取代,从顺式八面体转变为反式-[Cu(emizco)2(H2O)2]2+异构体。