Novel bis-arene (sandwich) complexes with NO+ acceptor. Isolation, X-ray crystallography and electronic structure

<div>The life-sustaining reduction of N2 to NH3 is thermoneutral yet kinetically challenged by high energy intermediates such as N2H2. Exploring intramolecular H-bonding as a potential strategy to stabilize diazene intermediates, we employ a series of [xHetTpCu]2(𝜇-N2H2) complexes that exhibit H-bonding between pendant aromatic N-heterocycles (XHet) such as pyridine and a bridging trans-N2H2 ligand at copper(I) centers. X-ray crystallography and IR spectroscopy clearly reveal H-bonding in [pyMeTpCu]2(𝜇-N2H2) while low temperature 1H NMR studies coupled with DFT analysis reveals a dynamic equilibrium between two closely related, symmetric H-bonded structural motifs. Importantly, the xHet pendant negligibly influences the electronic structure of xHetTpCuI centers in xHetTpCu(CNAr2,6-Me2) complexes that lack H-bonding as judged by nearly indistinguishable n(CN) frequencies (2113 - 2117 cm-1). Nonetheless, H-bonding in the corresponding [xHetTpCu]2(𝜇-N2H2) complexes results in marked changes in n(NN) (1398 - 1419 cm-1) revealed through rRaman studies. Due to the closely matched N-H BDE’s of N2H2 and the neutral pyH0 cation radical, the aromatic N-heterocylic pendants may encourage partial H-atom transfer (HAT) from N2H2 to xHet through redox non-innocent H-bonding in [xHetTpCu]2(𝜇-N2H2). DFT studies reveal modest thermodynamic barriers for concerted transfer of both H-atoms of coordinated N2H2 to the xHet pendants to generate tautomeric [xHetHTpCu]2(𝜇-N2) complexes, identifying concerted dual HAT as a thermodynamically favorable pathway for N2 / N2H2 interconversion.</div>

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X-Ray structures, Mössbauer hyperfine parameters, and molecular orbital descriptions of the phthalocyaninato iron(II) azole complexes

Journal of Porphyrins and Phthalocyanines ◽

10.1142/s1088424619502043 ◽

2020 ◽

Vol 24 (05n07) ◽

pp. 894-903

Author(s):

Dustin E. Nevonen ◽

Laura S. Ferch ◽

Victor Y. Chernii ◽

David E. Herbert ◽

Johan van Lierop ◽

...

Keyword(s):

Density Functional Theory ◽

Electronic Structure ◽

Dft Calculations ◽

Electronic Structures ◽

Density Functional ◽

Reasonable Agreement ◽

Hyperfine Parameters ◽

Functional Theory ◽

X Ray ◽

X Ray Crystallography

The electronic structures of a set of PcFe(azole)2 complexes (azole = imidazole, [Formula: see text]-methylimidazole, pyrazole, isoxazole, thiazole, 1,2,4-triazole, 3-amino-1,2,4,-triazole, and 5-amino-1,2,3,4-tetrazole) were examined by Mössbauer spectroscopy and Density Functional Theory (DFT) calculations. In addition, the geometric distortions in these compounds were elucidated by X-ray crystallography for imidazole, pyrazole, and thiazole-containing compounds. Predicted by DFT calculations, Mössbauer hyperfine parameters for all compounds are in reasonable agreement with experimental results, and the influence of the [Formula: see text]-donor and [Formula: see text]-acceptor properties of the axial azoles on the electronic structure of the PcFe(azole)2 complexes is demonstrated by comparison with the reference PcFePy2 compound.

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ChemInform Abstract: Molecular and Electronic Structure of the Confacial Diosmium(III) Nonabromide Complex Anion. X-Ray Crystallography of Rb3Os2Br9 and Direct Comparisons of (Os2Br9)3- with (Ru2Br9)3-.

ChemInform ◽

10.1002/chin.199515002 ◽

2010 ◽

Vol 26 (15) ◽

pp. no-no

Author(s):

S. F. GHELLER ◽

G. A. HEATH ◽

D. C. R. HOCKLESS ◽

D. G. HUMPHREY ◽

J. E. MCGRADY

Keyword(s):

Electronic Structure ◽

Complex Anion ◽

X Ray ◽

X Ray Crystallography ◽

Molecular And Electronic Structure

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Uncovering Redox Non-Innocent H-Bonding in Cu(I)-Diazene Complexes

10.26434/chemrxiv.14604483 ◽

2021 ◽

Author(s):

Evan Gardner ◽

Sean C. Marguet ◽

Caitlyn Cobb ◽

Dominic Pham ◽

Jeffery A. Bertke ◽

...

Keyword(s):

Electronic Structure ◽

Dynamic Equilibrium ◽

Cation Radical ◽

High Energy ◽

Dft Studies ◽

Nmr Studies ◽

X Ray ◽

X Ray Crystallography ◽

H Nmr ◽

Potential Strategy

<div>The life-sustaining reduction of N2 to NH3 is thermoneutral yet kinetically challenged by high energy intermediates such as N2H2. Exploring intramolecular H-bonding as a potential strategy to stabilize diazene intermediates, we employ a series of [xHetTpCu]2(𝜇-N2H2) complexes that exhibit H-bonding between pendant aromatic N-heterocycles (XHet) such as pyridine and a bridging trans-N2H2 ligand at copper(I) centers. X-ray crystallography and IR spectroscopy clearly reveal H-bonding in [pyMeTpCu]2(𝜇-N2H2) while low temperature 1H NMR studies coupled with DFT analysis reveals a dynamic equilibrium between two closely related, symmetric H-bonded structural motifs. Importantly, the xHet pendant negligibly influences the electronic structure of xHetTpCuI centers in xHetTpCu(CNAr2,6-Me2) complexes that lack H-bonding as judged by nearly indistinguishable n(CN) frequencies (2113 - 2117 cm-1). Nonetheless, H-bonding in the corresponding [xHetTpCu]2(𝜇-N2H2) complexes results in marked changes in n(NN) (1398 - 1419 cm-1) revealed through rRaman studies. Due to the closely matched N-H BDE’s of N2H2 and the neutral pyH0 cation radical, the aromatic N-heterocylic pendants may encourage partial H-atom transfer (HAT) from N2H2 to xHet through redox non-innocent H-bonding in [xHetTpCu]2(𝜇-N2H2). DFT studies reveal modest thermodynamic barriers for concerted transfer of both H-atoms of coordinated N2H2 to the xHet pendants to generate tautomeric [xHetHTpCu]2(𝜇-N2) complexes, identifying concerted dual HAT as a thermodynamically favorable pathway for N2 / N2H2 interconversion.</div>

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