Force Constants in Hydrogen and Deuterium Peroxides

Gigure, Paul A.; Bain, Osias

doi:10.1021/j150495a011

Cited by 32 publications

(5 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The S−S bonds in the disulfide complexes are generally weaker than the O−O bonds in the peroxide analogues (Table ). This is consistent with the weaker S−S bond in the free S 2 2- ( k S - S (S 2 2- ) = 1.88 mdyn/Å) 39 and H 2 S 2 ( k S - S (H 2 S 2 ) = 2.77 mdyn/Å) relative to the O−O bond in the free O 2 2- ( k O - O (O 2 2- ) = 2.76 mdyn/Å) 63 and H 2 O 2 ( k O - O (H 2 O 2 ) = 3.84 mdyn/Å), which is due to the more limited 3p − 3p interaction in S−S than the 2s/p − 2s/p hybrid interaction in O−O at bond distances of ∼2.1 and ∼1.4 Å, respectively.…”

Section: Discussionsupporting

confidence: 74%

Spectroscopy and Bonding in Side-On and End-On Cu₂(S₂) Cores: Comparison to Peroxide Analogues

et al. 2003

View full text Add to dashboard Cite

Spectroscopic methods combined with density functional calculations were used to study the disulfide-Cu(II) bonding interactions in the side-on micro -eta(2):eta(2)-bridged Cu(2)(S(2)) complex, [[Cu(II)[HB(3,5-Pr(i)(2)pz)(3)]](2)(S(2))], and the end-on trans- micro -1,2-bridged Cu(2)(S(2)) complex, [[Cu(II)(TMPA)](2)(S(2))](2+), in correlation to their peroxide structural analogues. Resonance Raman shows weaker S-S bonds and stronger Cu-S bonds in the disulfide complexes relative to the O-O and Cu-O bonds in the peroxide analogues. The weaker S-S bonds come from the more limited interaction between the S 3p orbitals relative to that of the O 2s/p hybrid orbitals. The stronger Cu-S bonds result from the more covalent Cu-disulfide interactions relative to the Cu-peroxide interactions. This is consistent with the higher energy of the disulfide valence level relative to that of the peroxide. The ground states of the side-on Cu(2)(S(2))/Cu(2)(O(2)) complexes are more covalent than those of the end-on Cu(2)(S(2))/Cu(2)(O(2)) complexes. This derives from the larger sigma-donor interactions in the side-on micro -eta(2):eta(2) structure, which has four Cu-disulfide/peroxide bonds, relative to the end-on trans- micro -1,2 structure, which forms two bonds to the Cu. The larger disulfide/peroxide sigma-donor interactions in the side-on complexes are reflected in their more intense higher energy disulfide/peroxide to Cu charge transfer transitions in the absorption spectra. The large ground-state covalencies of the side-on complexes result in significant nuclear distortions in the ligand-to-metal charge transfer excited states, which give rise to the strong resonance Raman enhancements of the metal-ligand and intraligand vibrations. Particularly, the large covalency of the Cu-disulfide interaction in the side-on Cu(2)(S(2)) complex leads to a different rR enhancement profile, relative to the peroxide analogues, reflecting a S-S bond distortion in the opposite directions in the disulfide/peroxide pi(sigma) to Cu charge transfer excited states. A ligand sigma back-bonding interaction exists only in the side-on complexes, and there is more sigma mixing in the side-on Cu(2)(S(2)) complex than in the side-on Cu(2)(O(2)) complex. This sigma back-bonding is shown to significantly weaken the S-S/O-O bond relative to that of the analogous end-on complex, leading to the low nu(S)(-)(S)/nu(O)(-)(O) vibrational frequencies observed in the resonance Raman spectra of the side-on complexes.

show abstract

Section: Discussionsupporting

confidence: 74%

Spectroscopy and Bonding in Side-On and End-On Cu₂(S₂) Cores: Comparison to Peroxide Analogues

et al. 2003

View full text Add to dashboard Cite

show abstract

“…This is consistent with other peroxo transition-metal complexes21 and with the 0-0 stretch for HOOH in the liquid phase (877 cm"1). 22 The 34-cm"1 shift (882 cm"1 -*• 848 cm"1) for the 180-labeled complex also is in accord with this assignment. The presence of a single line for the labeled compound indicates the complete incorporation of 180 (from the oxygenating agent, Phl,80) into the dioxygen group of the complex.…”

Section: Discussionsupporting

confidence: 57%

Preparation and characterization of a binuclear iron-.mu.-dioxygen complex: [(Ph3PO)4FeOOFe(OPPh3)4.cntdot.2H2O](ClO4)4

Sawyer¹,

McDowell²,

Spencer³

et al. 1989

Inorg. Chem.

View full text Add to dashboard Cite

Appendix m!(nl)! Consider a fixed molecular core geometry with m equivalent sites, each of which can be occupied by any one of n different metals. The number of possible metal stoichiometries is given by eq A I . The total number of discrete molecules, N , dependson the core geometry. Examples: (1) N = 24 when n = 4 for the trinuclear core structures VA and VB (Table V); (2) N = 36 when n = 4 for the tetrahedral core structure I11 (Table VI). The combination of [Fe"(OPPh3)4](C104)2 with HOOH, m-C1C6H4C(0)OOH, Me3COOH, PhIO, PhI(OAc)2, Bu4N(I04), 03, or NaOCl in anhydrous acetonitrile results in the formation of the binuclear complex [(Ph3P0)4FeOOFe(OPPh3)4.2H20] (C104)4(1). The same material is produced from the addition of HOOH plus two -OH ions to [Fe"'(Ph,P0)4](C104)3 in acetonitrile. The complex has been characterized by elemental analysis, electronic, vibrational, and ESR spectroscopy, solid-and solution-phase magnetic susceptibility measurements, and electrochemistry. Mechanistic pathways are proposed for the formation of 1 and for its reactivity with halide ions. The relative stability of the cis and trans isomers of the disubstituted d6 metal carbonyls M(C0)4L2 (M = Cr, Mo and L = NH3, PH,, C2H4) and M(CO)4LL' (M = Mo, L = C2H4, L' = CH2) has been studied theoretically through ab initio SCF calculations.Correlation effects were studied for Cr(CO),L2 with L = NH,, PH,, C2H4 through CAS S C F (complete active space SCF) calculations. The results may be summarized as follows: (i) for M(CO),L2, with L = NH,, PH,, the cis isomer is more stable than the trans one; (ii) for M(C0)4L2 with L = C2H4 or M(CO),LL' with L = C2H4 and L' = CH2, the trans isomer is more stable than the cis one; (iii) going from Cr to Mo increases the stability of the cis isomer for L = NH,, PH3 but decreases it for L = C2H4. These theoretical results are in excellent agreement with the bulk of structural data. The results for L = NH,, PH3 are understood easily in terms of competition for 7 back-bonding, but no simple rationale emerges for the greater stability of the trans structure in the case of ethylene or carbene ligands.

show abstract

“…Figure 2, which was constructed on the basis of our previous results, [38] displays the pattern of deconvoluted sub-band intensities (in % of the overall integrated intensity) for the temperature range 5 to 85 8C (symbols). If we focus on the intensity pattern of the three major sub-bands, which represent the three major hydrogen-bonded states of liquid water, we see that the intensities of sub-bands (2) and (4), which can be associated, respectively, with normal and very weak (probably bifurcated [35,36,43] ) hydrogen-bonded oscillators (Table 1), change dramatically with temperature in an almost perfectly anti-correlated manner. It should be stressed here that these temperature-induced spectral changes are really gigantic.…”

Section: Resultsmentioning

confidence: 99%

Local Dense Structural Heterogeneities in Liquid Water from Ambient to 300 MPa Pressure: Evidence for Multiple Liquid–Liquid Transitions

et al. 2004

View full text Add to dashboard Cite

Difference and double-difference near-infrared DO-D and HO-H stretching overtone (2nuOD and 2nuOH) spectroscopy and a rigorous (physically substantiated) band deconvolution technique were applied to reveal three different kinds of inherent (interstitial) structures of liquid water, which determine its high density (compared to ice lh under ambient conditions), its compressibility (under hydrostatic pressure, up to 300MPa), and its high fragility (manifested under temperature variation). Our data processing allowed the rigorous discrimination of up to six vibrational components. On the basis of an extensive comparative analysis combined with available structural data (X-ray and neutron scattering) and molecular dynamics (MD) simulations for liquid water, as well as with experimental and computed data for small non-tetrahedrally arranged water clusters, the major four components could be ascribed to: i) The basic lh icelike substructure; ii) the temperature-dependent remote interstitial "defects" due to tetrahedral displacements (primarily responsible for transport properties); iii) the interstitial "defects" most probably arranged in quasiplanar noncyclic tetramers (totally absent in the ice structure); and iv) the interstitial "defects" formed with increasing pressure, probably arranged in cubic water octamers and composed of two pairs of noncyclic and cyclic tetramer fragments. The latter structures include, essentially, bent hydrogen bonds stabilized by resonance effects.

show abstract

Force Constants in Hydrogen and Deuterium Peroxides

Cited by 32 publications

References 0 publications

Spectroscopy and Bonding in Side-On and End-On Cu₂(S₂) Cores: Comparison to Peroxide Analogues

Spectroscopy and Bonding in Side-On and End-On Cu₂(S₂) Cores: Comparison to Peroxide Analogues

Preparation and characterization of a binuclear iron-.mu.-dioxygen complex: [(Ph3PO)4FeOOFe(OPPh3)4.cntdot.2H2O](ClO4)4

Local Dense Structural Heterogeneities in Liquid Water from Ambient to 300 MPa Pressure: Evidence for Multiple Liquid–Liquid Transitions

Contact Info

Product

Resources

About

Force Constants in Hydrogen and Deuterium Peroxides

Cited by 32 publications

References 0 publications

Spectroscopy and Bonding in Side-On and End-On Cu2(S2) Cores: Comparison to Peroxide Analogues

Spectroscopy and Bonding in Side-On and End-On Cu2(S2) Cores: Comparison to Peroxide Analogues

Preparation and characterization of a binuclear iron-.mu.-dioxygen complex: [(Ph3PO)4FeOOFe(OPPh3)4.cntdot.2H2O](ClO4)4

Local Dense Structural Heterogeneities in Liquid Water from Ambient to 300 MPa Pressure: Evidence for Multiple Liquid–Liquid Transitions

Contact Info

Product

Resources

About

Spectroscopy and Bonding in Side-On and End-On Cu₂(S₂) Cores: Comparison to Peroxide Analogues

Spectroscopy and Bonding in Side-On and End-On Cu₂(S₂) Cores: Comparison to Peroxide Analogues