Synthesis and crystal structure of bis(μ2-acetato-κ2O:O′)-bis(μ2-1-(8-(2-oxidophenyl)-3,6-dioxa-2,7-diazaocta-1,7-dien-1-yl)naphthalen-2-olato-κ6O:O,N,N′,O′:O′)trizinc(II), C44H38Zn3N4O12