Table 1. Single crystal information for the compounds.

Compound	Crystal system	Space group	Symmetry	Polarity	ML activity
p-P4A	Monoclinic	P2(1)	Non-centrosymmetric	Polar	Active
p-P4Ac	Triclinic	P1[combining macron]	Centrosymmetric	Non-polar	Inactive
p-FP2A	Monoclinic	P2(1)/c	Centrosymmetric	Non-polar	Inactive
m-P4A	Monoclinic	P2(1)	Non-centrosymmetric	Polar	Active
p-P4A2	Orthorhombic	Pna2(1)	Non-centrosymmetric	Polar	Active