Did you forget to select the entire structure? Also, ChemDraw struggles with coordination complexes (common in inorganic chem). For organometallics, manually check the name.
: Scroll down to the "List of Available Software" and find ChemDraw under the chemistry or research tools section. chemdraw uottawa
Export as or SVG for vector graphics. A raster PNG will look blurry on a 36"x48" poster. Did you forget to select the entire structure