Electronic and structural data of 4’-substituted bis(2,2’;6’2’’-terpyridine)manganese in mono-, bis-, tris- and tetra-cationic states from DFT calculations

This data article provides density functional theory calculated structural (bond lengths and angles, coordinates of optimized geometries) and electronic (Mulliken spin population and character of frontier molecular orbitals) data of a series of 4’-substituted bis(2,2’;6’2’’-terpyridine)manganese complexes in four different oxidation states. The bis-cationic (n = 2) [Mn(tpy)2]2+ complexes are experimentally well known (Sjödin et al., 2008), while little or none experimental structural data of the tetra-cationic (n = 4, Romain et al., 2009, 2009), tris-cationic (n = 3, Romain et al., 2009) and mono-cationic (n = 1, Wang et al., 2014) [Mn(tpy)2]n+ complexes are available. For more insight into the provided data, see related research article “Redox chemistry of bis(terpyridine)manganese(II) complexes – a molecular view” (Conradie, 2022).


Specifications
Image, Graph, Figure  How the data were acquired Geometry optimizations and electronic structure calculations were done using the quantum computational chemistry program Gaussian

Value of the Data
• The data reported in this work will save computational time to calculate the structural and electronic structure of the tetra -cationic ( n = 4), tris -cationic ( n = 3), bis -cationic ( n = 2) and mono -cationic ( n = 1) [Mn(tpy) 2 ] n + complexes. The optimization of these geometries easy led to higher energy local minima structures when starting with a different input geometry. Some jobs ran more than 2 weeks on 2 nodes with 16 processors each before they converged. Little or no experimental structural data of these complexes are available [1][2][3][4] . • This data gives experimental chemists insight into the expected stability and reactivity of mono -, bis -, tris -and tetra -cationic states of [Mn(tpy) 2 ] n + complexes, that go through different oxidation states during catalytic cycles and electrochemical oxidation and reduction processes [5] . Transition metal-terpyridine complexes exhibit anti-microbial potential, are used in biomedical applications, and have unique optical, photo-luminescence-, catalytic-, photovoltaic-, sensitizers and sensor properties [6][7][8][9] . • This data provides the geometry of the basic structure of the ground states of mono -, bis -, tris -and tetra -cationic states of [Mn(tpy) 2 ] n + complexes, that include broken symmetry, constrained octahedral and compression Jahn-Teller geometries. The data can be used for the determination of the geometrical and electronic structures of related [Mn(tpy) 2 ] n + complexes, containing other tpy ligands.

Experimental Design, Materials and Methods
Geometry optimizations and electronic structure calculations were done by density functional theory (DFT) calculations using the Gaussian 16 software program (Revision B.01) [14] , similar to the computations described in the related research article [5] . The hybrid functional B3LYP [15 , 16] were used, while applying the GTO (Gaussian type orbital) triple-ζ basis set 6-311G(d,p) for the lighter atoms (C, H, N, F, O) and the def2-TZVPP basis set for both the core and va- Table 2 Mulliken spin density population on Mn and the two ligands (L1 and L2) of mono -, bis -, tris -and tetra -cationic states of [Mn(tpy) 2 ] n + complexes (1)- (6).  [17] was used, requesting a convergence on energy of 1.0D-8 atomic unit. The input coordinates for the compounds were constructed using Chemcraft software [18] . The coordinates, charge and multiplicity were specified in the input files of the DFT calculations. If difficulty with convergence were experienced, the options opt = (tight), Int = (Grid = Ultrafine) and scf = (qc,maxcycle = 10 0 0,tight,conver = 8) were specified in the input file. The geometrical parameters were obtained by visualizing the output files with the optimized structures in Chemcraft. Spin plots were obtained from cube files, generated with the cubegen keyword in Gaussian, and visualized in Chemcraft. Molecular orbital plots were generated in Chemcraft from the output files, with "gfinput POP(regular)" being specified in the input files. Many different input geometries with different Mn-N lengths, were optimized to ensure that the global minimum structure is indeed obtained, since many higher energy local minimum structures could also be optimized.

Ethics Statements
This work does not require any ethical statement.

Declaration of Competing Interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.