A prototype transition-metal olefin complex C2H4⋯AgCl synthesised by laser ablation and characterised by rotational spectroscopy and <i>ab initio</i> methods

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Pure rotational spectra of the ground vibrational states of six isotopologues of OC···AgI have been measured by chirped-pulse Fourier transform microwave spectroscopy. The spectra are assigned to determine the rotational constant, B(0), centrifugal distortion constant, D(J), and nuclear quadrupole coupling constant of the iodine atom, χ(aa)(I). The complex is linear. Isotopic substitutions at the silver, carbon, and oxygen atoms allow bond lengths to be established by the r(0), r(s), and r(m)((1)) methods of structure determination. The length of the C-O bond, r(CO), in the r(0) geometry for OC···AgI is 0.008 Å shorter than that found in the free CO molecule. The length of the Ag-I bond, r(AgI), is 0.013 Å shorter than in free AgI. χ(aa)(I) is determined to be -769.84(22) MHz for OC···(107)AgI implying an ionic character of 0.66 for the metal halide bond. Attachment of carbon monoxide to the isolated AgI molecule results in an increase of the ionic character of AgI of 0.12. The molecular structure and spectroscopic parameters determined from the experimental data are presented alongside the results of calculations at the explicitly correlated coupled-cluster singles, doubles and perturbative triples level. Vibrational frequencies, the electric dipole moment, the nuclear quadrupole coupling constant, and the dissociation energy of the molecule have been calculated.

Section: A Detection and Observation Of Rotational Transitionsmentioning

confidence: 99%

Molecular geometry of OC⋅⋅⋅AgI determined by broadband rotational spectroscopy and ab initio calculations

Stephens

Mizukami

Tew

et al. 2012

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“…The present work exploits the cold environment generated within a gas sample undergoing supersonic expansion to produce and isolate the H 3 N• • •CuCl monomer for study. It is informed by recent experiments which have succeeded in generating a wide variety of complexes that contain metal halides coordinated to simple Lewis bases such as N 2 , 7 H 2 , 8,9 CO, [10][11][12][13][14][15] H 2 O, [16][17][18] NH 3 , 19 H 2 S, 17,20,21 C 2 H 4 , 22,23 and C 2 H 2 . 22,24 Most pertinently, the spectra of five isotopologues of H 3 N• • • AgCl were characterised and analysed to reveal aspects of the molecular geometry.…”

Section: Introductionmentioning

confidence: 99%

A monomeric complex of ammonia and cuprous chloride: H3N⋯CuCl isolated and characterised by rotational spectroscopy and ab initio calculations

Bittner

Zaleski

Stephens

et al. 2015

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The H3N⋯CuCl monomer has been generated and isolated in the gas phase through laser vaporisation of a copper sample in the presence of low concentrations of NH3 and CCl4 in argon. The resulting complex cools to a rotational temperature approaching 2 K during supersonic expansion of the gas sample and is characterised by broadband rotational spectroscopy between 7 and 18.5 GHz. The spectra of six isotopologues are measured and analysed to determine rotational, B0; centrifugal distortion, DJ, DJK; and nuclear quadrupole coupling constants of Cu, Cl, and (14)N nuclei, χaa (X). The geometry of the complex is C3v with the N, Cu, and Cl atoms located on the a inertial axis. Bond distances and the ∠(H -N⋯Cu) bond angle within the complex are precisely evaluated through fitting of geometrical parameters to the experimentally determined moments of inertia and through ab initio calculations at the CCSD(T)(F12*)/AVQZ level. The r(Cu -Cl), r(Cu -N), and ∠(H -N⋯Cu) parameters are, respectively, evaluated to be 2.0614(7) Å, 1.9182(13) Å, and 111.40(6)° in the r0 geometry, in good agreement with the ab initio calculations. Geometrical parameters evaluated for the isolated complex are compared with those established crystallographically for a solid-state sample of [Cu(NH3)Cl].

“…44 Application of the Millen equations to complexes of the type B· · ·MX, where M = Cu, Ag, or Au appears to be less successful and, in those cases where k σ (or F 11 ) is available from ab initio calculations for comparison, it transpires that the Millen equations lead to k σ values that are too small. 26,29,30 On the other hand, the simple expression 1 in which B and MX are treated as point masses (that is, when B B and B MX in Eq. (19) become very large and the term in parentheses becomes unity),…”

Section: Comparison With the Millen Equations When Applied To Cmentioning

confidence: 99%

“…Recently, following the original work on complexes Rg· · ·MX and OC· · ·MX (M = Cu, Ag, or Au; X = F, Cl, Br, or I) by Gerry and co-workers, [4][5][6][7][8][9][10][11][12][13][14][15][16][17] we have been investigating systematically by rotational spectroscopy a wide range of complexes B· · ·MX involving another type of non-covalent interaction which links a coinage metal halide MX (M = Cu, Ag, or Au, X = F, Cl, or I) via the metal atom M to one of a number of small Lewis bases B (for example, B = N 2 , OC, NH 3 , HC≡ ≡CH, H 2 C= =CH 2 , (CH 2 ) 3 , H 2 O, and H 2 S). [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34] In the more strongly bound of these complexes, the approximations that B is unchanged on complex formation and that the intermolecular stretching force constant k σ is very much smaller than all stretching constants of the same symmetry are not valid and in particular the order k σ ≪ k MX does not hold. In such circumstances, the Millen equations are only approximate; recent work indicates that the diatomic approximation gives better agreement with results calculated ab initio.…”

Section: Introductionmentioning

confidence: 99%

“…In such circumstances, the Millen equations are only approximate; recent work indicates that the diatomic approximation gives better agreement with results calculated ab initio. 26,29,30 Here we present a model that is appropriate to a wide range of complexes B· · ·MX. It includes cases for which the two quadratic stretching force constants k σ and k MX are of similar magnitude, as well as those for which k σ ≪ k MX .…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A two force-constant model for complexes B⋯M–X (B is a Lewis base and MX is any diatomic molecule): Intermolecular stretching force constants from centrifugal distortion constants DJ or ΔJ

Bittner

Walker

Legon

2016

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A two force-constant model is proposed for complexes of the type B⋯MX, in which B is a simple Lewis base of at least C2v symmetry and MX is any diatomic molecule lying along a Cn axis (n ≥ 2) of B. The model assumes a rigid subunit B and that force constants beyond quadratic are negligible. It leads to expressions that allow, in principle, the determination of three quadratic force constants F11, F12, and F22 associated with the r(B⋯M) = r2 and r(M-X) = r1 internal coordinates from the equilibrium centrifugal distortion constants DJ (e) or ΔJ (e), the equilibrium principal axis coordinates a1 and a2, and equilibrium principal moments of inertia. The model can be applied generally to complexes containing different types of intermolecular bond. For example, the intermolecular bond of B⋯MX can be a hydrogen bond if MX is a hydrogen halide, a halogen-bond if MX is a dihalogen molecule, or a stronger, coinage-metal bond if MX is a coinage metal halide. The equations were tested for BrCN, for which accurate equilibrium spectroscopic constants and a complete force field are available. In practice, equilibrium values of DJ (e) or ΔJ (e) for B⋯MX are not available and zero-point quantities must be used instead. The effect of doing so has been tested for BrCN. The zero-point centrifugal distortion constants DJ (0) or ΔJ (0) for all B⋯MX investigated so far are of insufficient accuracy to allow F11 and F22 to be determined simultaneously, even under the assumption F12 = 0 which is shown to be reasonable for BrCN. The calculation of F22 at a series of fixed values of F11 reveals, however, that in cases for which F11 is sufficiently larger than F22, a good approximation to F22 is obtained. Plots of F22 versus F11 have been provided for Kr⋯CuCl, Xe⋯CuCl, OC⋯CuCl, and C2H2⋯AgCl as examples. Even in cases where F22 ∼ F11 (e.g., OC⋯CuCl), such plots will yield either F22 or F11 if the other becomes available.