Spin Transitions in Iron(II) Complexes

Transition metal complexes of 6‐mercaptopurine: Characterization, Theoretical calculation, DNA‐Binding, molecular docking, and anticancer activity

“…The [Fe(6‐MP) 2 Cl 2 ] magnetic moment was 0.796 BM, which is in the range of the low spin d 6 Fe(II) complexes and for diamagnetic properties. [ 45 ] Thus, the electron spectrum between 800 and 1,100 nm does not have any observed peak, which indicates the octahedral arrangement around the metal. [ 45,46 ] The Racah and nephelauxetic parameter values of Ni(II) and Co(II) were calculated using standard equations.…”

“…[ 45 ] Thus, the electron spectrum between 800 and 1,100 nm does not have any observed peak, which indicates the octahedral arrangement around the metal. [ 45,46 ] The Racah and nephelauxetic parameter values of Ni(II) and Co(II) were calculated using standard equations. [ 47 ] The value for the Co(II) complex indicated a considerable ionic character for new σ bonds because they were close to their unity value, whereas Ni(II) has a combination of covalence and ionic character for the newly formed bonds.…”

Spin Transition Sensors Based on β-Amino-Acid 1,2,4-Triazole Derivative

“…The white color of 1 · 0.5H 2 O , is due to the location of the spin-allowed lowest energy d-d transition, 5 T 2g → 5 E g , for the HS sites in the near infrared region (∼11,500 cm −1 ) [ 25 , 26 ]. Two supplementary bands, corresponding to the 1 A 1g → 1 T 1g and 1 A 1g → 1 T 2g d-d transitions of LS Fe II sites are observed at ∼18,727 cm −1 and ∼30,300 cm −1 , respectively suggesting that some proportion of Fe II may be in the LS state at room temperature.…”

“…Two supplementary bands, corresponding to the 1 A 1g → 1 T 1g and 1 A 1g → 1 T 2g d-d transitions of LS Fe II sites are observed at ∼18,727 cm −1 and ∼30,300 cm −1 , respectively suggesting that some proportion of Fe II may be in the LS state at room temperature. The ligand field strengths for the HS and the LS state, given by equations 10D q HS = E( 5 E) − E( 5 T 2 ) and 10D q LS = E( 1 T) − E( 1 A 1 ) + (E( 1 T 2 ) − E( 1 T 1 ))/4, [ 25 , 26 ] allowed us to estimate 10D q HS and 10D q LS to be approximately 11,500 cm −1 and 26,302 cm −1 , respectively. These values are characteristic for SCO complexes [ 25 , 26 ].…”

“…The ligand field strengths for the HS and the LS state, given by equations 10D q HS = E( 5 E) − E( 5 T 2 ) and 10D q LS = E( 1 T) − E( 1 A 1 ) + (E( 1 T 2 ) − E( 1 T 1 ))/4, [ 25 , 26 ] allowed us to estimate 10D q HS and 10D q LS to be approximately 11,500 cm −1 and 26,302 cm −1 , respectively. These values are characteristic for SCO complexes [ 25 , 26 ]. Presence of LS state at room temperature has been confirmed by 57 Fe Mössbauer spectroscopy (vide infra).…”