TY - JOUR

T1 - Two isostructural complexes of Ni(II) and Zn(II) with violurate and pyridine: A detailed structural, theoretical, magnetic, and NMR investigation

AU - Roy, Subhadip

AU - Mal, Susital

AU - Banik, Rupak

AU - Das, Subrata

AU - Dlháň, Lubor

AU - Titis, Jan

AU - Boca, Roman

AU - Kirillov, Alexander

AU - Novikov, Alexander S.

AU - Hazendonk, Paul

AU - Butcher, R. J.

AU - Bauza, Antonio

AU - Frontera, Antonio

PY - 2023/11/7

Y1 - 2023/11/7

N2 - Synthesis and detailed investigation of two dimethylviolurate complexes are reported herein. Two new metal( ii ) complexes [M(dmv) 2 (py) 2 ]·3H 2 O {M = Ni (1), Zn (2)} were self-assembled from a metal( ii ) chloride salt, N , N ′-dimethylvioluric acid (Hdmv), and pyridine (py). They were isolated as stable crystalline solids and characterized, including by single crystal X-ray diffraction. Structures 1 and 2 are composed of discrete [M(dmv) 2 (py) 2 ] blocks in which the six-coordinate metal( ii ) atoms show a slightly distorted {MN 4 O 2 } octahedral geometry. The adjacent [M(dmv) 2 (py) 2 ] units are hydrogen bonded with an involvement of disordered water clusters into 1D H-bonded chains. DFT calculations were used to analyse the unconventional anti-parallel CO⋯CO interaction observed between the monomeric units in 1 and 2. Complex 1 also refers to an elongated tetragonal bipyramid for which a positive zero-field splitting is confirmed by magnetic studies. The complex matches the magnetostructural D -correlation for hexacoordinate Ni( ii ) complexes with moderate structural and magnetic anisotropy with D str = +7.45 pm, and D mag = +5.11 cm −1 . Solution state NMR spectroscopy reveals a slow isomerization process related to the bidentate- N , O and bidentate- O , O coordination of dimethylviolurate in 2, with the barrier ranging from 76.4 to 77.9 kJ mol −1 . The 1 H NMR spectra confirm the presence of three water molecules which exhibit significant chemical shift dependence on temperature indicating strong binding to the complex in solution phase.

AB - Synthesis and detailed investigation of two dimethylviolurate complexes are reported herein. Two new metal( ii ) complexes [M(dmv) 2 (py) 2 ]·3H 2 O {M = Ni (1), Zn (2)} were self-assembled from a metal( ii ) chloride salt, N , N ′-dimethylvioluric acid (Hdmv), and pyridine (py). They were isolated as stable crystalline solids and characterized, including by single crystal X-ray diffraction. Structures 1 and 2 are composed of discrete [M(dmv) 2 (py) 2 ] blocks in which the six-coordinate metal( ii ) atoms show a slightly distorted {MN 4 O 2 } octahedral geometry. The adjacent [M(dmv) 2 (py) 2 ] units are hydrogen bonded with an involvement of disordered water clusters into 1D H-bonded chains. DFT calculations were used to analyse the unconventional anti-parallel CO⋯CO interaction observed between the monomeric units in 1 and 2. Complex 1 also refers to an elongated tetragonal bipyramid for which a positive zero-field splitting is confirmed by magnetic studies. The complex matches the magnetostructural D -correlation for hexacoordinate Ni( ii ) complexes with moderate structural and magnetic anisotropy with D str = +7.45 pm, and D mag = +5.11 cm −1 . Solution state NMR spectroscopy reveals a slow isomerization process related to the bidentate- N , O and bidentate- O , O coordination of dimethylviolurate in 2, with the barrier ranging from 76.4 to 77.9 kJ mol −1 . The 1 H NMR spectra confirm the presence of three water molecules which exhibit significant chemical shift dependence on temperature indicating strong binding to the complex in solution phase.

UR - https://www.mendeley.com/catalogue/63882fbd-3ee7-3648-b6a1-c792e9f354d8/

U2 - 10.1039/d3ce00871a

DO - 10.1039/d3ce00871a

M3 - Article

JO - CrystEngComm

JF - CrystEngComm

SN - 1466-8033

ER -