“It reeks of chic,” says event planner to the stars Colin Cowie, of the duplex penthouse he has put on the market for $5.75 million. The 15-story modern edifice of limestone and gray brick — named The Emory and located in Manhattan’s historic Flatiron district — is by Morris Adjmi Architects. Cowie closed on the top two units in 2009 and proceeded to customize the resulting nearly 3,000-square-foot space into a glamorous couture haven where he could host his legendary parties. The apartment, available with furnishings for an additional sum, is awash in materials and surfaces that emanate shimmer and shine.