Structure Elucidation of an Yttrium Diethyldithiocarbamato‐Phenanthroline Complex by X‐ray Crystallography, Solid‐State NMR, and ab‐initio Quantum Chemical Calculations

Abstract

We present a structural analysis method for molecular and electronic structure of yttrium diethyldithiocarbamato‐phenanthroline complex {[Y(S2CNR2)3PHEN] with R = C2H5 and PHEN = 1,10‐phenanthroline} combining solid‐state NMR spectroscopy, XRD, and first principles DFT calculations. Replacing the Nd3+ ion with Y3+ in the reported crystal structure of [Nd(S2CNR2)3PHEN] complex generated an approximate 3D structure of the title complex. The structure was then subjected to first principles quantum chemical geometry optimisation using periodic DFT method. The quality of the method is discussed by comparing predicted and experimental powder XRD patterns. Full assignment of 13C and 15N solid‐state CP‐MAS NMR spectra as well as analyses of the principal values of the chemical shift tensors were carried out using periodic scalar relativistic DFT modelling. Spin‐orbit relativistic effects, estimated by SO‐ZORA formalism for one molecular unit, were evaluated. Finally, the X‐ray structure of the title complex was determined, which proved that the former procedure is appropriate. The most important orbital interactions were investigated by Natural Bond Orbital analysis. The isotropic shielding values for S2CN‐carbons were analysed by Natural Localised Molecular Orbital analysis. The present approach can be further extended to study other rare earth metal complexes, particularly those having similar but not yet solved crystal structures.

Relativistic Heavy-Neighbor-Atom Effects on NMR Shifts: Concepts and Trends Across the Periodic Table

“…The SO-HALA effects in early transition-metal complexes have not been investigated as much as those of the late transition metals but a short overview of relativistic NMR effects in d 0 complexes of early transition metals was contained in a recently published larger review . Available data confirm that the SO-HALA effects for d 0 complexes are uniformly deshielding, in contrast to the increasingly shielding contributions in d 2 and d 4 systems. ,,, …”

“…138 Available data confirm that the SO-HALA effects for d 0 complexes are uniformly deshielding, in contrast to the increasingly shielding contributions in d 2 and d 4 systems. 100,137,146,155 An analysis of the relativistic 13 C NMR shifts in early transition-metal complexes was used to elucidate the link between the NMR shifts and the electronic structure in d 0 Schrock alkylidene methathesis catalysts based on Mo, Ta, W, and Re. 156 The high-frequency 13 C signals in these complexes were attributed to the large paramagnetic contributions caused by the small energy separations between the σ M−C and π M−C * orbitals.…”

NMR crystallography of molecular organics

“…Relativistic effects can mostly be ignored for molecular organics, although contributions to the shielding of light atoms from relativistic Heavy Atom effects on neighbouring Light Atoms (HALA effects) are commonly encountered [85]. For example, changes in 13 C shift of about 5.5 ppm were seen for carbon bonded to sulfur [91,92]. Other examples are discussed in Section 3.4.3.…”

Structural insights into the polymorphism of bismuth(III) di-n-butyldithiocarbamate by X-ray diffraction, solid-state (13C/15N) CP-MAS NMR and DFT calculations

“…In this work, we apply the so called "SMARTER Crystallography" approach [21][22][23][24][25][26], which enables the combination of experimental solid-state NMR and XRD techniques with theoretical calculations of structure and NMR chemical shifts of periodic systems, aiming to gain much greater insights into the structure and properties of materials, than by any individual approach considered alone. In our previous reports, we have successfully used a similar multidisciplinary approach for structural investigations of the yttrium(III) [27] and lanthanum(III) [28] complexes with diethyldithiocarbamate and phenanthroline ligands.…”