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Abstract Coordination complexes of general formulatrans‐[MX2(R2ECH2CH2ER2)2] (MII=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 VIIcomplexes 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 TiIIand CrIIcomplexes. 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 VIIin this environment, but also on differences between N and P donor ligands, a key comparison in coordination chemistry.
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Pushing the boundaries: enhancing TiO 2 performance for hydrogen evolution under visible light photocatalysis by incorporating RuO 2
The careful modulation of RuO2content in TiO2nanostructures plays a crucial role in optimizing photochemical properties resulting in water splitting under visible light, making them promising candidates for solar-driven hydrogen generation.
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- Award ID(s):
- 2425119
- PAR ID:
- 10609685
- Publisher / Repository:
- Royal Society of Chemistry
- Date Published:
- Journal Name:
- Sustainable Energy & Fuels
- Volume:
- 9
- Issue:
- 10
- ISSN:
- 2398-4902
- Page Range / eLocation ID:
- 2707 to 2717
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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The crystal structure of the title compound, hexaaquanickel(II) dichloride–1,4,7,10,13,16-hexaoxacyclooctadecane–water (1/2/2), [Ni(H2O)6]Cl2·2C12H24O6·2H2O, is reported. The asymmetric unit contains half of the Ni(OH2)6moiety with a formula of C12H32ClNi0.50O10at 105 K and triclinic (P1) symmetry. The [Ni(OH2)6]2+cation has close to ideal octahedral geometry with O—Ni—O bond angles that are within 3° of idealized values. The supramolecular structure includes hydrogen bonding between the water ligands, 18-crown-6 molecules, Cl−anions, and co-crystallized water solvent. Two crown ether molecules flank the [Ni(OH2)6]2+molecule at the axial positions in a sandwich-like structure. The relatively symmetric hydrogen-bonding network is enabled by small Cl−counter-ions and likely influences the more idealized octahedral geometry of [Ni(OH2)6]2+.more » « less
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- Free Publicly Accessible Full Text
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Accepted Manuscript
- Journal Article:
- https://doi.org/10.1039/D5SE00040H
