Synthesis and structure of a supramolecular octanuclear Cu(II) complex <f>{[Cu(sae)]<sub>4</sub>2CH<sub>3</sub>OH·H<sub>2</sub>O}<sub>2</sub></f> through both <f>μ</f>-oxo and hydrogen bonds (sae = 2-salicylideneamino-1-ethanol)