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1. Comparison of Experimental vs Theoretical Abundances of ¹³ CH ₃ D and ¹² CH ₂ D ₂ for Isotopically Equilibrated Systems from 1 to 500 °C

   https://doi.org/10.1021/acsearthspacechem.9b00244  

   Eldridge, Daniel L.; Korol, Roman; Lloyd, Max K.; Turner, Andrew C.; Webb, Michael A.; Miller, Thomas F.; Stolper, Daniel A. (November 2019, ACS Earth and Space Chemistry)
2. Late 3 d -Transition Metal Complexes Bearing a Bis -Phosphine Borane Ligand, PhB(CH ₂ P ^t Bu ₂ ) ₂

   https://doi.org/10.1021/acs.organomet.2c00378  

   Handford, Rex C.; Zhong, Lingfei; Tilley, T. Don (September 2022, Organometallics)
3. Computer‐Assisted 3D Structure Elucidation (CASE‐3D): The Structural Value of ² J _CH in Addition to ³ J _CH Coupling Constants

   https://doi.org/10.1002/ange.201915103  

   Koos, Martin R. M.; Navarro‐Vázquez, Armando; Anklin, Clemens; Gil, Roberto R. (January 2020, Angewandte Chemie)

   Abstract We present a method to use long‐range CH coupling constants to derive the correct diastereoisomer from the molecular constitution of small molecules. A set of 79²J_CHand³J_CHvalues collected from a single HSQMBC experiment on a sample of strychnine were used in the CASE‐3D (computer‐assisted 3D structure elucidation) protocol. In addition to the most commonly used³J_CHcoupling constants, the subset of 32²J_CHvalues alone showed an excellent degree of configuration selection. The study is mainly based on comparison of DFT‐calculated^2,3J_CHvalues with experimental ones, critical for the case of²J_CH. But the configuration selection also works well using³J_CHvalues predicted from a semi‐empirical Karplus‐based equation limited to H−C−C−C fragments. The robustness, shown using strychnine as a proof of concept, makes theJ‐based CASE‐3D analysis a viable option for the application in fields such as peptide and carbohydrate research, organic synthesis, natural‐product identification and analysis, as well as medicinal chemistry. 

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4. Helium Nanodroplet Infrared Spectroscopic Studies of CH ₄ ⁺ and ¹³ CH ₃ ⁺

   https://doi.org/10.1021/acs.jpca.4c06858  

   Singh, Amandeep; Allison, Sofia H; Azhagesan, Andrew_Abhisek A; Vilesov, Andrey F (December 2024, The Journal of Physical Chemistry A)
5. Electronic Structure of trans‐ [V ^II Cl ₂ (E(CH ₃ ) ₂ CH ₂ CH ₂ E(CH ₃ ) ₂ ) ₂ ], E=N, P

   https://doi.org/10.1002/ejic.202400395  

   Jafari, Mehrafshan_G; Zolnhofer, Eva_M; Fehn, Dominik; Heinemann, Frank_W; Opalade, Adedamola_A; Carroll, Patrick_J; Meyer, Karsten; Krzystek, J.; Ozarowski, Andrew; Mindiola, Daniel_J; et al (December 2024, European Journal of Inorganic Chemistry)

   Abstract Coordination complexes of general formulatrans‐[MX₂(R₂ECH₂CH₂ER₂)₂] (M^II=Ti, V, Cr, Mn; E=N or P; R=alkyl or aryl) are a cornerstone of coordination and organometallic chemistry. We investigate the electronic properties of two such complexes,trans‐[VCl₂(tmeda)₂] andtrans‐[VCl₂(dmpe)₂], which thus representtrans‐[MX₂(R₂ECH₂CH₂ER₂)₂] where M=V, X=Cl, R=Me and E=N (tmeda) and P (dmpe). These V^IIcomplexes haveS=3/2 ground states, as expected for octahedral d³. Their tetragonal distortion leads to zero‐field splitting (zfs) that is modest in magnitude (D≈0.3 cm⁻¹) relative to analogousS=1 Ti^IIand Cr^IIcomplexes. This parameter was determined from conventional EPR spectroscopy, but more effectively from high‐frequency and ‐field EPR (HFEPR) that determined the sign ofDas negative for the diamine complex, but positive for the diphosphine, which information had not been known for anytrans‐[VX₂(R₂ECH₂CH₂ER₂)₂] systems. The ligand‐field parameters oftrans‐[VCl₂(tmeda)₂] andtrans‐[VCl₂(dmpe)₂] are obtained using both classical theory andab initioquantum chemical theory. The results shed light not only on the electronic structure of V^IIin this environment, but also on differences between N and P donor ligands, a key comparison in coordination chemistry. 

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