Four new Mn(II) inorganic-organic hybrid frameworks with diverse inorganic magnetic chain's sequences: syntheses, structures, magnetic, NLO, and dielectric properties.
Four new inorganic-organic hybrid manganese frameworks, formulated as [Mn(Am-Hip)2]·3H2O (1), [Mn2(ip)2(H2O)]·CH3OH (2), [Mn2(OH-ip)2(DMF)]·DMF (3), and (Me2NH2)[Mn4(sdba)4(Hsdba)(H2O)]·3H2O·2DMF (4) (Am-H2ip = 5-aminoisophthalic acid, H2ip = isophthalic acid, OH-H2ip = 5-hydroxyisophthalic acid, and H2sdba = 4,4'-sulfonyldibenzoic acid), have been prepared by solvothermal reactions of Mn(II) ions with different polycarboxylate acids in the presence of LiNO3 or NH4NO3. Single-crystal X-ray diffraction studies reveal that the frameworks of 1-4 contain diverse Mn(II)-oxygen inorganic magnetic chain's sequences, -J1J1J1J1- for 1, -J1J2J1J2- for 2, -J1J1J2J2- for 3, and -J1J2J3J3- for 4. The sequence in 4 has never been seen for the magnetic chain compounds and is a new type of magnetic alternating sequence. Magnetic investigations indicate that these compounds all show weak antiferromagnetic couplings between the adjacent Mn(II) ions. Magnetostructural analyses based on the data of 1-4 and other related Mn(II) chain compounds imply that the magnitude of the magnetic coupling has some relationship with the Mn-O-Mn angle of the μ2-O bridge and the average Mn-O-C-O torsion angle of the carboxylate bridges. Compounds 2 and 4 crystallize in chiral and acentric space groups, and they both exhibit powder second harmonic generation (SHG) efficiencies approximately 0.6 and 0.9 times, respectively, that of the standard potassium dihydrogen phosphate (KDP) powder. In addition, the dielectric properties of 2 and 4 were also investigated.
State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences , Fuzhou, Fujian 350002, P. R. China.
Chong-Bin
CB
Tian
Chao
C
He
Yun-Hu
YH
Han
Qi
Q
Wei
Qi-Peng
QP
Li
Ping
P
Lin
Shao-Wu
SW
Du