Ring Contracted 16π Tetrathia Core-Modified Isophlorin

Ethylene bridged 16π [2.2.2.2] tetrathiaisophlorin represents a novel example for the ring contracted isophlorin, where all the thiophenes are connected only through α, β position, along with E-form of ethylene bridge. It was synthesized through McMurry coupling of appropriate dialdehydes. Single Crystal X-ray diffraction studies displayed the planar con-formation of the macrocycle along with all thiophene and ethylene protons. 1H NMR studies confirms the paratropic ring current of the macrocycle, where all the ethylene protons resonate in downfield. Two 8π cyclooctatetraenes, were isolated as racemic mixture having the puckered 4nπ ring.