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Title: Direct Characterization of a Reactive Lattice-Confined Ru 2 Nitride by Photocrystallography

Abstract

Reactive metal–ligand (M–L) multiply bonded complexes are ubiquitous intermediates in redox catalysis and have thus been long-standing targets of synthetic chemistry. The intrinsic reactivity of mid-to-late M–L multiply bonded complexes renders these structures challenging to isolate and structurally characterize. Although synthetic tuning of the ancillary ligand field can stabilize M–L multiply bonded complexes and result in isolable complexes, these efforts inevitably attenuate the reactivity of the M–L multiple bond. Here, we report the first direct characterization of a reactive Ru2 nitride intermediate by photocrystallography. Photogeneration of reactive M–L multiple bonds within crystalline matrices supports direct characterization of these critical intermediates without synthetic derivatization.

Authors:
ORCiD logo; ; ; ORCiD logo
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
Sponsoring Org.:
UNIVERSITY
OSTI Identifier:
1377921
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of the American Chemical Society; Journal Volume: 139; Journal Issue: 8
Country of Publication:
United States
Language:
ENGLISH
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY

Citation Formats

Das, Anuvab, Reibenspies, Joseph H., Chen, Yu-Sheng, and Powers, David C.. Direct Characterization of a Reactive Lattice-Confined Ru 2 Nitride by Photocrystallography. United States: N. p., 2017. Web. doi:10.1021/jacs.6b13357.
Das, Anuvab, Reibenspies, Joseph H., Chen, Yu-Sheng, & Powers, David C.. Direct Characterization of a Reactive Lattice-Confined Ru 2 Nitride by Photocrystallography. United States. doi:10.1021/jacs.6b13357.
Das, Anuvab, Reibenspies, Joseph H., Chen, Yu-Sheng, and Powers, David C.. Thu . "Direct Characterization of a Reactive Lattice-Confined Ru 2 Nitride by Photocrystallography". United States. doi:10.1021/jacs.6b13357.
@article{osti_1377921,
title = {Direct Characterization of a Reactive Lattice-Confined Ru 2 Nitride by Photocrystallography},
author = {Das, Anuvab and Reibenspies, Joseph H. and Chen, Yu-Sheng and Powers, David C.},
abstractNote = {Reactive metal–ligand (M–L) multiply bonded complexes are ubiquitous intermediates in redox catalysis and have thus been long-standing targets of synthetic chemistry. The intrinsic reactivity of mid-to-late M–L multiply bonded complexes renders these structures challenging to isolate and structurally characterize. Although synthetic tuning of the ancillary ligand field can stabilize M–L multiply bonded complexes and result in isolable complexes, these efforts inevitably attenuate the reactivity of the M–L multiple bond. Here, we report the first direct characterization of a reactive Ru2 nitride intermediate by photocrystallography. Photogeneration of reactive M–L multiple bonds within crystalline matrices supports direct characterization of these critical intermediates without synthetic derivatization.},
doi = {10.1021/jacs.6b13357},
journal = {Journal of the American Chemical Society},
number = 8,
volume = 139,
place = {United States},
year = {Thu Feb 16 00:00:00 EST 2017},
month = {Thu Feb 16 00:00:00 EST 2017}
}
  • Thermally-reversible solid-state linkage SO2 photoisomers of three complexes in the [Ru(NH3)4SO2X]tosylate2 family are captured in their metastable states using photocrystallography, where X = pyridine (1), 3-Cl-pyridine (2) and 4-Cl-pyridine (3). This photoisomerism only exists in the single-crystal form; accordingly, the nature of the crystalline environment surrounding the photo-active species controls its properties. In particular, the structural role of the tosylate anion needs to be understood against possible chemical influences due to varying the trans ligand, X. The photo-excited geometries, photoconversion levels and thermal stabilities of the photoisomers that form in 1-3 are therefore studied. 1 and 2 yield two photo-isomersmore » at 100 K: the O-bound end-on n1-SO2 Page 1 of 32 ACS Paragon Plus Environment The Journal of Physical Chemistry (MS1) configuration and the side-bound n2-SO2 (MS2), while 3 only exhibits the more thermally stable MS2 geometry. The decay kinetics of the MS2 geometry for 1-3 demonstrate that the greater the free volume of the GS SO2 ligand for a given counterion, the greater the MS2 thermal stability. Furthermore, a rationalization is sought for the SO2 phototriggered molecular rotation of the phenyl ring in the tosylate anion; this is selectively observed in 2, manifesting as nanomechanical molecular transduction. This molecular transduction was not observed in 1, despite the presence of the MS1 geometry due to the close intermolecular interactions between the MS1 SO2 and the neighbouring tosylate ion. The decay of this anionic molecular rotor in 2, however, follows a non-traditional decay pathway, as determined by time-resolved crystallographic analysis; this contrasts with the well-behaved first-order kinetic decay of its MS1 SO2 phototrigger.« less
  • Five new Ru[sub I]-Ru[sup I] tetracarbonyl complexes, including two incorporating polyoxoanion ligands, have been prepared: [(P[sub 3]O[sub 9])[sub 2]Ru[sub 2](CO)[sub 4]][sup 4[minus]] (1), [(Cp[sup *]TiW[sub 5]O[sub 18])[sub 2]Ru[sub 2](CO)[sub 4]][sup 4[minus]] (2), [(CH[sub 3]CN)[sub 6]Ru[sub 2](CO)[sub 4]][sup 2+] (3), [(PPh[sub 3])[sub 2](CH[sub 3]CN)[sub 4]Ru[sub 2]-(CO)[sub 4]][sup 2+] (4), and [(C[sub 5]H[sub 5]N)[sub 6]Ru(CO)[sub 4]][sup 2+] (5). Two of these complexes were structurally characterized in the solid state using single-crystal X-ray diffraction techniques: complex 1 as a solvated tetra-n-butylammonium salt [[(P[sub 3]O[sub 9])[sub 2]Ru[sub 2](CO)[sub 4]](TBA)[sub 4][center dot]2CH[sub 3]CN: a = 11.737(1) [angstrom], b = 16.166(3) [angstrom], c = 24.583(7) [angstrom],more » [beta] = 100.19(2)[degrees], Z = 2, space group P2[sub 1]/c-C[sup 5][sub 2h]] and complex 4 as a hexafluorophosphate salt [[(PPh[sub 3])[sub 2](CH[sub 3]CN)[sub 4]Ru[sub 2](CO)[sub 4]](PF[sub 6])[sub 2]: a = 29.157(5) [angstrom], b = 9.341(2) [angstrom], c = 20.673(3) [angstrom], [beta] = 108.40(5)[degrees], Z = 4, space group C2/c-C[sup 6][sub 2h]]. The remaining were formulated and assigned structures on the basis of their elemental compositions. NMR spectra, and infrared spectra. Complex 3 proved to be a reactive precursor to a variety of Ru[sup I]-Ru[sup I] tetracarbonyl complexes, including complexes 1, 2, 4, and 5.« less
  • The reaction of Ru/sub 3/(CO)/sub 9/(..mu../sub 3/-S)/sub 2/ (2) with Ru/sub 3/(CO)/sub 12/ under UV irradiation has yielded the higher nuclearity cluster compounds Ru/sub 4/(CO)/sub 9/(..mu..-CO)/sub 2/(..mu../sub 4/-S)/sub 2/ (3), 38%, Ru/sub 5/(CO)/sub 14/(..mu../sub 4/-S)/sub 2/ (4), 20%, and Ru/sub 6/(CO)/sub 17/(..mu../sub 4/-S)/sub 2/ (5), 3%. Thermal decarbonylation of Ru/sub 3/(CO)/sub 9/(..mu../sub 3/-CO)(..mu../sub 3/-S) (1) at 100/sup 0/C has yielded 3, 47%, 5, 10%, and Ru/sub 7/(CO)/sub 20/(..mu../sub 4/-S)/sub 2/ (6), 26%. The large clusters are decomposed to 2 and 3 by reaction with CO at 1 atm. Compounds 4-6 have been characterized by single-crystal X-ray diffraction analyses. For 4:more » space group P2/sub 1//n, a = 8.787 (2) A, b = 14.550 (3) A, c = 19.741 (3) A, ..beta.. = 98.09 (1)/sup 0/, Z = 4, rho/sub calcd/ = 2.56 g/cm/sup 3/. The cluster consists of an approximately square arrangement of four ruthenium atoms with quadruply bridging sulfido ligands on each face. An Ru(CO)/sub 4/ unit bridges one Ru-Ru edge of the cluster. But the EAN rule the molecule is unsaturated, and one of the Ru-Ru bonds was found to be unusually short, 2.704 (1) A. For 5: space group P2/sub 1/2/sub 1/2/sub 1/, a = 11.211 (2) A, b = 14.666 (4) A, c = 17.611 (4) A, Z = 4, rho/sub calcd/ = 2.63 g/cm/sup 3/. Compound 5 is isomorphous and isostructural with the know osmium homologue. The molecule consists of a pentagonal-bypyramidal cluster of five ruthenium atoms with two sulfido ligands. A Ru(CO)/sub 4/ group bridges one apical-equatorial edge of the cluster. For 6: space group P2/sub 1/2/sub 1/2/sub 1/, a = 11.226 (3) A, b = 14.320 (4) A, c = 21,217 (5) A, Z = 4, rho/sub calcd/ = 2.59 g/cm/sup 3/. Compound 6 is isomorphous and isostructural with the known osmium homologue. The molecule consists of a pentagonal-bipyramidal cluster of five ruthenium atoms and two sulfido ligands. Two Ru(CO)/sub 4/ groups bridge symmetrically adjacent apical-equatorial edges of the cluster.« less
  • Ru{sub 2}(O{sub 2}C(CH{sub 2}){sub 6}CH{sub 3}){sub 4} (1a) is soluble in both coordinating (THF, CH{sub 3}OH, CH{sub 3}CN) and noncoordinating solvents (benzene, toluene, cyclohexane, CH{sub 2}Cl{sub 2}), allowing its solution properties to be investigated by {sup 1}H and {sup 13}C NMR spectroscopy, UV/visible spectroscopy, resonance Raman spectroscopy, and cyclic voltammetry. In noncoordinating solvents, 1a exists as an oligomer, presumably by way of axial intermolecular -(--[Ru{sub 2}]--O--){sub n}-interactions. {sup 1}H NMR studies of 1a and [Ru{sub 2}(O{sub 2}C(CH{sub 2}){sub 6}CH{sub 3}){sub 4}]{sup +}[X]{sup {minus}}([1a]{sup +}[X]{sup {minus}}), where X = Cl, BF{sub 4}, or O{sub 2}C(CH{sub 2}){sub 6}CH{sub 3}, indicate that bothmore » dipolar and contact mechanisms contribute to the paramagnetic shifts of the protons. Resonances for axial and equatorial ligands are shifted upfield and downfield, respectively, by a dipolar mechanism. Aromatic ligands in the axial sites, e.g. pyridine and pyrazine, experience an enhanced upfield shift by direct {pi}-delocalization. Comparison of the {sup 1}H NMR signals for M{sub 2}(O{sub 2}CR){sub 4} compounds where M = Ru and O{sub 2}CR = benzoate, toluate, butyrate, crotonate, and dimethylacrylate with those where M = Mo indicates that the equatorial carboxylate ligands in the diruthenium species also experience {pi}-contact shifts. Variable-temperature studies and calculated estimates of dipolar shifts indicate a significant zero-field splitting contribution to the dipolar shift. The arrangements of the toluate rings in Ru{sub 2}(O{sub 2}C -p-tolyl){sub 4}-(THF){sub 2}, Ru{sub 2}(O{sub 2}C-p-tolyl){sub 4}(CH{sub 3}CN){sub 2}, and [Ru{sub 2}(O{sub 2}C-p-tolyl){sub 4}(THF){sub 2}]{sup +}[BF{sub 4}]{sup {minus}} deviate by 15(1), 2.3(2), and 7.3{degrees}, respectively, form alignment with the Ru-Ru axis.« less
  • In order to find new ruthenium complexes with [RuPS{sub 2}N{sub 2}] frameworks, [Ru(PPr{sub 3}){sub 2}(`S{sub 2}N{sub 2}H{sub 2}`)] (2), (`S{sub 2}N{sub 2}H{sub 2}`{sup 2-} = 1,2-ethanediamine-N,N` -bis(2-benzenethiolate)(2-)), [Ru(CO)(PPr{sub 3})(`S{sub 2}N{sub 2}H{sub 2}`)] (7), [Ru(CO)(PCy{sub 3})(`S{sub 2}N{sub 2}H{sub 2}`)] (4), [Ru(PCy{sub 3})(`S{sub 2}N{sub 2}`)] (5), (`S{sub 2}N{sub 2}`{sup 4-} = 1,2-ethanediamide-N,N` -bis(2-benzenethiolate)(4-)), [Ru(Br)(PPh{sub 3})- (`Et{sub 2}S{sub 2}N{sub 2}H{sub 2}`)] Br (8), (`Et{sub 2}S{sub 2}N{sub 2}H{sub 2}` = 1,10-diethyl-2,3,8,9-dibenzo-1,10-dithia-4,7-diazadecane), and [Ru(Br)- (PPh{sub 3})(`(PhCH{sub 2}){sub 2}S{sub 2}N{sub 2}H{sub 2}`)]Br (9) (`(PhCH{sub 2}){sub 2}S{sub 2}N{sub 2}H{sub 2}` = 1,10-dibenzyl-2,3,8,9-dibenzo-1,10-dithia-4,7-diazadecane) were synthesized. The molecular structures of 2, 5 and 9 were elucidated by X-ray structuremore » determination. (2: triclinic space group P1; a = 11.103(3) {Angstrom}, b = 11.720(2) {Angstrom}, c = 13.813(3) {Angstrom}; {alpha} = 79.43(2){degrees}, {beta} = 85.73(2){degrees}, {gamma} = 82.91(2){degrees};Z = 2; R/R{sub w} = 5.1/4.6%. 5: monoclinic space group P2{sub 1}/n; a = 12.019(4) {Angstrom}, b = 15.132% (6) {Angstrom}, c = 33.566(11) {Angstrom}; {beta} = 90.56(3) {Angstrom}{degrees}; Z = 8; R/R{sub w} = 5.0/4.7%. 9: monoclinic space group Cc; a = 17.839(9) {Angstrom}, b = 15.846(8) {Angstrom}, C = 15.706(10) {Angstrom}; {beta} = 109.18(5){degrees}; Z =4;R/R{sub w} = 6.0/6.0%.) 2 and 9 exhibit pseudooctahedral six-coordinate Ru(II) centers.« less