Spiro-conjugated indenodiarylethenes: enabling steric-induced electronic tuning of photochromic and photoluminescent properties by spiro-conjugation螺共轭的茚二芳基乙烯: 通过螺共轭实现空间诱导的光致变色和光致发光性能的电子调谐SCIENCE CHINA-CHEMISTRYIF9.72020-08-219PREAI