Table 2. Summary of Packing, Secondary Interactions, and Percent Intensity Decreases for trans-1-(n-pyridyl)-2-(m-pyridyl)ethylene (Where n and/or m = 2, 3, or 4) Using PXRD^a.

n,m′-bpe	packing	π–π stacking	average percent intensity decrease
2,2′-bpe*	1D corrugated chains	yes	22.6
2,3′-bpe	1D corrugated chains	no	31.9
2,4′-bpe	1D corrugated chains	no	13.3
3,3′-bpe	1D infinite chains	no	23.7
3,4′-bpe	1D corrugated chains	no	54.4
4,4′-bpe	2D network	yes	2.56

^aThe asterisk (*) indicates that the sample consists of two polymorphs.