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

Abstract

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].

Molecular geometries and other properties of H2O⋯AgI and H3N⋯AgI as characterised by rotational spectroscopy and ab initio calculations

“…Similar arguments to those presented above explain the absence of K 1 = 1 transitions for the partially deuterated isotopologues of NH 3 · · · AgI, an observation consistent with previous results obtained through studies of H 3 N· · · MX complexes. 12,13 C. Molecular geometry Figures 3 and 4, respectively, show the model geometries of the H 2 O· · · AgI and H 3 N· · · AgI complexes. Structural parameters in these models were directly fitted to moments of inertia using Kisiel's STRFIT program 41 to yield r 0 results.…”

“…A very similar trend was observed in the equivalent L· · · CuCl series. 4,6,10,12 The variation in χ aa (Cl) provides an indication of the extent of electron redistribution accompanying the formation of each of these complexes. Evidently, stabilisation of OC· · · MCl through back-donation of electrons from d orbitals of the metal onto π* orbitals of CO leads to a stronger interaction than that existing within Ar· · · MCl.…”

The covalent interaction between dihydrogen and gold: A rotational spectroscopic study of H2–AuCl

“…eQq197 (Au) = −41.0(18) • eQq( 35 Cl) − 2501(96) MHz with an R 2 = 0.996 fits the data without the experimental H 2 -AuCl data and with this data becomes eQq 197 (Au) = −41.4(15) • eQq( 35 Cl) − 2529(75) MHz with an R 2 = 0.996.…”

“…9 Unlike the coinage metal studies, these systems were found to have van der Waals interaction energies (≤18 kJ mol 1 ) 10 and larger Ar-M distances. More recently, Walker, Legon, and co-workers have investigated the MX interaction with both polar [11][12][13][14][15][16][17][18][19][20] and non-polar polyatomic molecules. [21][22][23] In all MX studies listed above, the nuclear quadrupole coupling constant (NQCC), or eQq, has served as a probe for the change in the electronic structure of the metal when present.…”

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

“…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.…”