First-row transition metal–pyridine (py)–sulfate [(py)xM](SO4) complexes (M= Ni, Cu and Zn): crystal field theory in action

2018 ◽  
Vol 74 (3) ◽  
pp. 263-268 ◽  
Author(s):  
Mrittika Roy ◽  
Duyen N. K. Pham ◽  
Ava Kreider-Mueller ◽  
James A. Golen ◽  
David R. Manke
Keyword(s):  
Crystal Structure ◽  
Field Theory ◽  
Transition Metal ◽  
Crystal Field ◽  
Crystal Field Theory ◽  
Coordination Environment ◽  
Pyridine Ligands ◽  
Zinc Coordination ◽  
Sulfate Complexes ◽  
Cu And Zn

The crystal structures of three first-row transition metal–pyridine–sulfate complexes, namelycatena-poly[[tetrakis(pyridine-κN)nickel(II)]-μ-sulfato-κ2O:O′], [Ni(SO4)(C5H5N)4]n, (1), di-μ-sulfato-κ4O:O-bis[tris(pyridine-κN)copper(II)], [Cu2(SO4)2(C5H5N)6], (2), andcatena-poly[[tetrakis(pyridine-κN)zinc(II)]-μ-sulfato-κ2O:O′-[bis(pyridine-κN)zinc(II)]-μ-sulfato-κ2O:O′], [Zn2(SO4)2(C5H5N)6]n, (3), are reported. Ni compound (1) displays a polymeric crystal structure, with infinite chains of NiIIatoms adopting an octahedral N4O2coordination environment that involves four pyridine ligands and two bridging sulfate ligands. Cu compound (2) features a dimeric molecular structure, with the CuIIatoms possessing square-pyramidal N3O2coordination environments that contain three pyridine ligands and two bridging sulfate ligands. Zn compound (3) exhibits a polymeric crystal structure of infinite chains, with two alternating zinc coordination environments,i.e.octahedral N4O2coordination involving four pyridine ligands and two bridging sulfate ligands, and tetrahedral N2O2coordination containing two pyridine ligands and two bridging sulfate ligands. The observed coordination environments are consistent with those predicted by crystal field theory.

More crystal field theory in action: the metal–4-picoline (pic)–sulfate [M(pic) x ]SO4 complexes (M = Fe, Co, Ni, Cu, Zn, and Cd)

2019 ◽  
Vol 75 (5) ◽  
pp. 568-574 ◽  
Author(s):  
Duyen N. K. Pham ◽  
Mrittika Roy ◽  
Ava Kreider-Mueller ◽  
James A. Golen ◽  
David R. Manke
Keyword(s):  
Crystal Structure ◽  
Field Theory ◽  
Crystal Structures ◽  
Crystal Field ◽  
Crystal Field Theory ◽  
Iron Cobalt ◽  
Coordination Environment ◽  
Trigonal Bipyramidal ◽  
Cobalt Nickel ◽  
Sulfate Complexes

Seven crystal structures of five first-row (Fe, Co, Ni, Cu, and Zn) and one second-row (Cd) transition metal–4-picoline (pic)–sulfate complexes of the form [M(pic) x ]SO4 are reported. These complexes are catena-poly[[tetrakis(4-methylpyridine-κN)metal(II)]-μ-sulfato-κ2 O:O′], [M(SO4)(C6H7N)4] n , where the metal/M is iron, cobalt, nickel, and cadmium, di-μ-sulfato-κ4 O:O-bis[tris(4-methylpyridine-κN)copper(II)], [Cu2(SO4)2(C6H7N)6], catena-poly[[bis(4-methylpyridine-κN)zinc(II)]-μ-sulfato-κ2 O:O′], [Zn(SO4)(C6H7N)2] n , and catena-poly[[tris(4-methylpyridine-κN)zinc(II)]-μ-sulfato-κ2 O:O′], [Zn(SO4)(C6H7N)3] n . The Fe, Co, Ni, and Cd compounds are isomorphous, displaying polymeric crystal structures with infinite chains of M II ions adopting an octahedral N4O2 coordination environment that involves four picoline ligands and two bridging sulfate anions. The Cu compound features a dimeric crystal structure, with the CuII ions possessing square-pyramidal N3O2 coordination environments that contain three picoline ligands and two bridging sulfate anions. Zinc crystallizes in two forms, one exhibiting a polymeric crystal structure with infinite chains of ZnII ions adopting a tetrahedral N2O2 coordination containing two picoline ligands and two bridging sulfate anions, and the other exhibiting a polymeric crystal structure with infinite chains of ZnII ions adopting a trigonal bipyramidal N3O2 coordination containing three picoline ligands and two bridging sulfate anions. The structures are compared with the analogous pyridine complexes, and the observed coordination environments are examined in relation to crystal field theory.

Synchrotron X-ray analysis of the electron density in CoF2 and ZnF2

2001 ◽  
Vol 57 (2) ◽  
pp. 128-135 ◽  
Author(s):  
Nicholas J. O'Toole ◽  
Victor A. Streltsov
Keyword(s):  
Field Theory ◽  
Transition Metal ◽  
Electron Density ◽  
Crystal Field ◽  
Room Temperature ◽  
Crystal Field Theory ◽  
X Ray ◽  
Structure Factors ◽  
Small Crystals ◽  
Multipole Refinement

Accurate structure factors for small crystals of the rutile-type structures CoF2, cobalt difluoride, and ZnF2, zinc difluoride, have been measured with focused λ = 0.8400 (2) Å synchrotron X-radiation at room temperature. Phenomenological structural trends across the full series of rutile-type transition metal difluorides are analysed, showing the importance of the metal atom in the degree of distortion of the metal–F6 octahedra in these structures. Multipole models reveal strong asphericities in the electron density surrounding the transition metals, which are consistent with expectations from crystal field theory and the structural trends in these compounds. Transition metal 3d-orbital populations were computed from the multipole refinement parameters, showing significant repopulation of orbitals compared with the free atom, particularly for CoF2.

scholarly journals Crystal Field Theory of Magnetic Behaviour of Er2(SO4)3·8H2O

1996 ◽  
Vol 89 (5-6) ◽  
pp. 649-655
Author(s):  
R. Gupta ◽  
U.S. Ghosh ◽  
C. Basu
Keyword(s):  
Field Theory ◽  
Crystal Field ◽  
Magnetic Behaviour ◽  
Crystal Field Theory

scholarly journals Advances of crystal field theory and exchange charge model

2019 ◽  
Vol 21 (4) ◽  
Author(s):  
M.G. Brik ◽  
◽  
N.M. Avram ◽  
C.N. Avram ◽  
◽  
...  
Keyword(s):  
Field Theory ◽  
Crystal Field ◽  
Crystal Field Theory ◽  
Charge Model ◽  
Exchange Charge Model
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