A new Zn/O single source precursor, TMEDA-Zn$(eacac)_2$, has been synthesized by using N, N, N’, N’-tetramethylethylendiamine (TMEDA), sodium ethyl-acetoacetate, and $ZnCl_2$. From this organometallic precursor, ZnO thin films have been successfully grown on Si (100) substrates through the metal organic chemical vapor deposition (MOCVD) method at relatively mild conditions in the temperature range of 390~430 ${^{circ}C}$. The synthesized ZnO films have been found to possess average grain sizes of about 70 nm with an orientation along the c-axis. The precursor and ZnO films are characterized through infrared spectroscopy, nuclear magnetic resonance spectroscopy, EI-FAB-spectroscopy, elemental analyses, thermal analysis, X-ray diffraction, and field emission scanning electron microscopic analyses.