Jose Alberto Guerrero Cruz

• Cerpa, Erick; Cruz, Jose Alberto Guerrero; Merino, Gabriel; Jimenez-Halla, J. Oscar C. & Castro, Abril C. (2025). Covalent bonding and extreme shielding in xenon–icosagen fluoride cations. Physical Chemistry, Chemical Physics - PCCP. ISSN 1463-9076. doi: 10.1039/d5cp03397g. Full text in Research Archive Show summary

  Although icosagen cations are known to interact significantly with noble gases, well-defined examples exhibiting strong binding energies indicative of covalent character, particularly for the heavier icosagens, remain scarce. In this work, we explore the stability and bonding of a series of XeEF2+ and Xe2EF2+ (E = B–Tl) cations, focusing on global-minimum structures featuring Xe–E bonds. Ab initio calculations indicate that these species are thermodynamically viable at 298 and 398 K, with all considered dissociation pathways being endergonic. Bonding analyses reveal strong covalent Xe–icosagen interactions for B, Al, and Ga, while In and Tl exhibit weaker bonding character that suggests more ionic interactions, as supported by the selected complementary analyses. Fluoride ion affinities and relativistic 129Xe NMR chemical shifts further support the strong electron-withdrawing nature of the EF2+ cations. Overall, the results suggest that, beyond the previously reported XeBF2+, Xe–icosagen compounds such as XeAlF2+ and XeGaF2+ may also be experimentally accessible.

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• Cruz, Jose Alberto Guerrero; Lersch, Martin; Tilset, Mats & Castro, Abril C (2025). Analyzing the electronic structure of Pt(II) Complexes via 195-Pt NMR. Full text in Research Archive Show summary

  Nuclear Magnetic Resonance (NMR) is a powerful spectroscopic technique to determine the structure of transition-metal complexes. In addition to structural information, NMR also offers insights into the electronic structure of these complexes. The chemical shift is, in fact, directly linked to the frontier molecular orbitals, and thus to reactivity [1,2]. Platinum complexes containing diimine ancillary ligands are promising candidates for C-H bonding activation under direct oxidative conditions [3]. Variations on the ancillary ligands modify the local environment of the Pt nucleus, producing a broad range of 195-Pt NMR chemical shifts. Hence, a molecular approach can help to rationalize the signature of the complexes and to establish correlations with descriptors such as the empirical Hammett’s parameters. In this work, we investigate an extensive series of diimine and bipyridine complexes of neutral and cationic Pt(II) species. Calculations at the two-component relativistic level successfully reproduce the 195-Pt NMR chemical shifts experimental trends. We found a linear correlation with the empirical Hammett’s parameters for both neutral and cationic species. In addition, the Natural Chemical Shift (NCS) [4] analysis, reveals the most deshielded principal component of diimines lies parallel to the bonding plane in contrast to the perpendicular orientation reported for PtL4 systems. [5] Moreover, the (de)shielding across the series of Pt-species is clearly affected by the antibonding 𝜎*(Pt-L) orbital energy, which is determined by the electron-donating or –withdrawing character of the substituents in the diimine and bipyridine ligands, as well as the monodentate ligands bonded to Pt. [1] M. Kaupp, M. Bühl, V. G. Malkin, Eds. In Calculation of NMR and EPR Parameters: Theory and applications. Wiley-VCH, Weinheim, 2004. [2] C. P. Gordon, L. Lätsch, C. Copéret, J. Phys. Chem. Lett. 2021, 12, 8, 2072-2085. [3] M. Lersch, M. Tilset, Chem. Rev. 2005, 105, 2471−2526. [4] J. A. Bohmann, F. Weinhold, T. C. Farrar, J. Chem. Phys. 1997, 107, 1173–1184. [5] A. Venkatesh, D. Gioffre, B.A. Atterberry, L. Rochlitz, S.L. Carnahan, Z. Wang, G. Menzildjian, A. Lesage, C. Coperet, A.J. Rossini, J. Am. Chem. Soc. 2022, 144, 13511-13525.

• Cruz, Jose Alberto Guerrero & Aguilera, Abril Castro (2024). Understanding the electronic properties of Pt(II) complexes via 195Pt NMR chemical shifts. Full text in Research Archive
• Cruz, Jose Alberto Guerrero; Schröder, Mirjam; Corzilius, Björn; Beweries, Torsten & Castro, Abril (2024). Describing the Electronic Structure of Group-4 Metallocenes with 19F-NMR Chemical Shifts. Full text in Research Archive Show summary

  Nuclear Magnetic Resonance (NMR) is an important technique for the characterization of transition-metal complexes. Beyond structural information, NMR offers insights into the complexes’ electronic structure, since there is a direct relationship between the NMR chemical shift and the frontier molecular orbitals. The Group-4 metallocenes with bis-η5 cyclopentadienyl ligands are important examples of catalysts used in olefin insertion process. Studying the behavior of the shielding effects in these complexes is of relevance to understand their reactivity.

• Cruz, Jose Alberto Guerrero; Tilset, Mats & Castro, Abril C (2023). Understanding Electronic Properties of Pt(II) Complexes via 195Pt NMR Chemical Shifts. Full text in Research Archive
• Cruz, Jose Alberto Guerrero; Tilset, Mats & Castro, Abril C (2023). Molecular approach to the 195Pt NMR chemical shifts of square-planar Pt(II) complexes with diimine ancillary ligands. Full text in Research Archive
• Guerrero, Jose Alberto Cruz; Tilset, Mats & Castro, Abril C (2022). The influence of substituents and the environment on the 195Pt NMR chemical shifts of square-planar Pt complexes with ancillary ligands. Full text in Research Archive Show summary

  Abstract. The modelling of NMR parameters in transition-metal complexes is challenging due to the extreme sensitivity to relativistic and solvent effects. In this work we are modeling the 195Pt NMR chemical shifts in a series of Pt(II) complexes with diimine ancillary ligands, where the goal is to explore the substituent effects of the ancillary ligands on the 195Pt chemical shifts. The analysis at the relativistic 2c-ZORA/COSMO level is used to gain further insight into the bonding and stability of these complexes.

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