In 2021, Kurmoo and co-workers reported two polymorphic coordination polymers , The magnetic studies for 27 were performed from 2 to 350 K in 1000 Oe (Fig. ). The T of 2.28 cm 3 mol -1 K at 350 K indicated that almost 70% [LS-LS] fractions converted to [HS-HS] fractions. Then the gradual reduction in T value with decrease in temperature and reaching a plateau at 1.13 cm 3 mol -1 K around 90 K suggested the occurrence of SCO in Fe(II) center. Below 28 K, the T product decreased to 0.71 cm 3 mol -1 K till 2 K and it is due to the zero-field splitting of the residuary HS Fe(II) centers as well as antiferromagnetic interactions among Fe(II) centers. To correlate the SCO and fluorescence properties in 27, temperature-dependent fluorescence emission study was performed from 90 to 300 K (Fig. ). For 27, upon heating, the fluorescence intensity increased gradually and reached highest around 140 K followed by a decrease again till 160 K. Further above 160 K to 180 K, the intensity began to increase rapidly and decreased while further heated . These extreme temperature-dependent anomaly in fluorescence intensity happened in the measured temperature range of 90-300 K and agreed quite well with the thermoinduced SCO behavior of 27. Also, to further support this hypothesis, they have shown the normalized derivative of T and fluorescence intensity curve for 27 within 90-300 K (heating mode) (Fig. ). The SCO profile obtained from this plot for 27 obtained are well accordant to the variations in fluorescence intensity, demonstrating the fluorescence intensity change was associated to the SCO transition.