Steric Control over Supramolecular Polymer Formation in trans-1,2-Bis(4-pyridyl)ethylene Adducts of Zinc Xanthates: Implications for Luminescence
Steric control over supramolecular aggregation is demonstrated for a series of adducts formed between Zn(S2COR)2 and trans-1,2-bis(4-pyridyl)ethylene, whereby supramolecular zigzag polymers are found when R is small, that is, Et (1) and n-Bu (2), but only bimetallic aggregates could be formed when R...
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Veröffentlicht in: | Crystal growth & design 2010-03, Vol.10 (3), p.1247-1256 |
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Format: | Artikel |
Sprache: | eng |
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Zusammenfassung: | Steric control over supramolecular aggregation is demonstrated for a series of adducts formed between Zn(S2COR)2 and trans-1,2-bis(4-pyridyl)ethylene, whereby supramolecular zigzag polymers are found when R is small, that is, Et (1) and n-Bu (2), but only bimetallic aggregates could be formed when R = Cy (3). This results in different coordination geometries: four-coordinate N2S2 zinc in 1 and 2, and five-coordinate NS4 zinc in 3, a feature which greatly influences photophysical responses in the solid state. When excited in the UV region, {Zn(S2COEt)2L}∞ (1) and {[Zn(S2COCy)2]2L} (3) produce broad luminescence in the visible region. Five-coordinate 3 produces more broad and intense luminescence than four-coordinate 1. The configuration interaction singles (CIS) and post-Hartree−Fock (HF) calculations for 1 and 3 indicate the A-band excited state is responsible for the observed luminescence which is strongly associated with charge transfer from S and Zn. |
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ISSN: | 1528-7483 1528-7505 |
DOI: | 10.1021/cg9012735 |