Pulsed-field ionization electron spectroscopy and conformation of copper-diammonia

Shenggang Li, Bradford R. Sohnlein, Dong Sheng Yang, Jun Miyawaki, Ko Ichi Sugawara

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12 Scopus citations

Abstract

Copper-diammonia, Cu (N H3) 2, and its deuterated species, Cu (N D3) 2, are produced in supersonic molecular beams and studied by pulsed-field ionization zero electron kinetic energy photoelectron spectroscopy and ab initio calculations. Structural isomers with a copper atom binding to an ammonia dimer or two ammonia molecules are obtained by the calculations. By comparing the experimental measurements to the theoretical calculations, the neutral and ionic forms of copper-diammonia are determined to be in a doubly bound linear conformation in their ground electronic states. The adiabatic ionization potentials of Cu (N H3) 2 and Cu (N D3) 2 are measured as 29 532 (5) and 29 313 (5) cm-1, respectively. The metal-ligand symmetric stretching frequencies are measured to be 436 cm-1 for Cu+ - (N H3) 2 and 398 cm-1 for Cu+ - (N D3) 2, and the metal-ligand bending frequencies 75139 cm-1 for Cu Cu+ - (N H3) 2 and 70125 cm-1 for Cu Cu+ - (N D3) 2. Moreover, the dissociation energy of Cu (N H3) 2 →CuN H3 +N H3 is determined to be 11 (3) kcal mol-1 through a thermodynamic relationship.

Original languageEnglish
Article number214316
JournalJournal of Chemical Physics
Volume122
Issue number21
DOIs
StatePublished - Jun 1 2005

Bibliographical note

Funding Information:
This work was supported by the Physical Chemistry Program of the National Science Foundation and the donors of the Petroleum Research Fund of the American Chemical Society. Table I. Energies with vibrational zero-point corrections (a.u.), geometries (angstroms, degrees) [free N H 3 : N – H = 1.014 Å and ∠ H – N – H = 108.0 ° . Free ( N H 3 ) 2 : N ⋯ H = 2.254 Å , N ⋯ N = 3.261 Å , ∠ N – H ⋯ N = 168.9 ° ], and vibrational frequencies ( cm − 1 ) of Cu ( N H 3 ) 2 and Cu – ( N H 3 ) 2 from B 3 LYP ∕ 6 ‐ 311 + G ( d , p ) calculations. Energy Bond lengths Bond angles Frequencies D 3 d       A 1 g 2 Cu – N = 2.007 ∠ Cu – N – H = 111.9 a 1 g : 3319, 1207, 302 − 1753.594 198 N – H = 1.025 ∠ H – N – H = 106.9 e g : 3428, 1628, 547       a 1 u : 43       a 2 u : 3288, 1208, 419       e u : 3420, 1626, 490, 68 A 1 g 1 Cu – N = 1.941 ∠ Cu – N – H = 112.3 a 1 g : 3445, 1324, 412 − 1753.449 683 N – H = 1.020 ∠ H – N – H = 106.5 e g : 3530, 1667, 652       a 1 u : 35       a 2 u : 3444, 1324, 511       e u : 3530, 1667, 698, 136 D 3 h       A 1 ′ 2 Cu – N = 2.007 ∠ Cu – N – H = 111.9 a 1 ′ : 3319, 1206, 302 − 1753.594 197 N – H = 1.025 ∠ H – N – H = 106.9 e ′ : 3420, 1627, 490, 68       a 1 ″ : 47       a 2 ″ : 3289, 1208, 419       e ″ : 3428, 1627, 547 A 1 ′ 1 Cu – N = 1.941 ∠ Cu – N – H = 112.3 a 1 ′ : 3445, 1324, 412 − 1753.449 593 N – H = 1.020 ∠ H – N – H = 106.5 e ′ : 3531, 1668, 698, 136 ( − 1751.905 396 )     a 1 ″ : 28       a 2 ″ : 3444, 1324, 511       e ″ : 3530, 1666, 652 C s       A ′ 2 Cu – N = 2.073 ∠ Cu – N – H = 109.5 a ′ : 3581, 3489, 3466, 3279, 1666, 1649, 1212, − 1753.591 197 N – H = 1.031 ∠ N – H ⋯ N = 168.1 1095, 642, 318, 274, 190, 35   H ⋯ N = 2.062 ∠ H – N ⋯ N = 8.0 a ″ : 3590, 3553, 1696, 1667, 508, 332, 184, 31   N ⋯ N = 3.078     A ′ 1 Cu – N = 1.933 ∠ Cu – N – H = 112.6 a ′ : 3559, 3474, 3459, 2855, 1674, 1659, 1393, − 1753.389 389 N – H = 1.057 ∠ N – H ⋯ N = 177.0 1217, 855, 484, 398, 234, 78   H ⋯ N = 1.846 ∠ H – N ⋯ N = 1.9 a ″ : 3561, 3534, 1714, 1671, 744, 456, 290, 22   N ⋯ N = 2.902     Table II. ZEKE peak positions ( cm − 1 ) and assignments. [The assignments associated with 7 1 1 are tentative (see text for details). The numbering of the vibrational modes is based on the D 3 d point group.] Cu ( N H 3 ) 2 Cu ( N D 3 ) 2 Assignments 29 526 29 306 7 1 1 29 532 29 313 0 0 0 29 586 29 361 7 1 1 14 1 1 29 596 29 368 14 1 1 29 650 29 418 7 1 1 14 2 2 29 659 29 427 14 2 2 29 716 29 476 7 1 1 14 3 3 29 724 29 483 14 3 3 29 810 29 563 14 0 2 29 862 29 609 7 1 1 4 1 3 29 870 29 617 14 1 3 29 961 29 704 3 0 1 7 1 1 29 968 29 711 3 0 1 30 020 29 760 3 0 1 7 1 1 14 1 1 30 031 29 768 3 0 1 14 1 1 30 082 29 816 3 0 1 7 1 1 14 2 2 30 094 29 825 3 0 1 14 2 2 30 244   3 0 1 14 0 2 30 394 30 099 3 0 2 7 1 1 30 401 30 107 3 0 2 Table III. Adiabatic ionization potentials (AIPs) and metal-ligand vibrational frequencies of Cu ( N H 3 ) 2 and Cu ( N D 3 ) 2 in cm − 1 . The numbering of the vibrational modes is based on the D 3 d point group.   Cu ( N H 3 ) 2 Cu ( N D 3 ) 2 ZEKE B3LYP ZEKE B3LYP AIP 29 532 (5) 31 739 29 313 (5) 31 512 Cu + – N stretch ( ν 3 + , a 1 g ) 436 412 398 377 N – Cu + – N bend ( ν 14 + , e u ) 139 136 125 123 N–Cu–N bend ( ν 14 , e u ) 75 68 70 63 Table IV. Adiabatic ionization potentials and metal-ammonia bond dissociation energies ( D 0 ∕ D 0 + ) of the ground electronic states of M ( N H 3 ) n and M + ( N H 3 ) 2 ( M = Cu , Ag ; n = 1 , 2 ) .   AIP (eV) D 0 ( kcal mol − 1 ) D 0 + ( kcal mol − 1 ) Experiment a Theory Experiment Theory Cu 7.726 38 b         Cu N H 3 5.7613 (6) c 11(4) 9.1, d 10.9, e 13.1, f 14.1, h 10.5 k 57 (4) f 57.3, d 51.6, e 51.8, i 54.6, j 51.6, l 52.0 m Cu ( N H 3 ) 2 3.6615 (6) n 11 (2) 6.7, d 8.0 e 59 (2) f 53.1, d 52.2, e 51.6, i 59.4, j Ag 7.576 24 b         Ag N H 3 5.8992 (6) c 2 (3) 7.5, g 4.3, k 4.6, o 6.0 q 41 (3) p 46.1, o 45.4 q Ag ( N H 3 ) 2 5.2 r     37 (1) s   a Calculated from D 0 + ( Cu L n − 1 + − L ) − D 0 ( Cu L n − 1 − L ) = AIP ( Cu L n − 1 ) − AIP ( Cu L n ) . b Reference 7 . c Reference 9 , ZEKE. d This work, B3LYP. e This work, CCSD(T)∕∕B3LYP. f Reference 5 , CID. g Reference 36 , B3P86. h Reference 37 , LCGTO-DF. i Reference 10 , MCPF. j Reference 11 , MP4(SDTQ). k Reference 34 , CCSD(T). l Reference 40 , CCSD(T)∕∕MP2. m Reference 41 , CCSD(T)(full). n This work, ZEKE. o Reference 38 , MP2. p Reference 6 , CID. q Reference 39 , CASPT2. r Reference 29 , PIE, and no error bar given. s Reference 30, van’t Hoff Plot. FIG. 1. Structural isomers of copper-diammonia from B 3 LYP ∕ 6 ‐ 311 + G ( d , p ) calculations. (a) D 3 d , Cu ∕ Cu + – ( N H 3 ) 2 , (b) D 3 h , Cu ∕ Cu + – ( N H 3 ) 2 , (c) C s eclipsed, Cu ( N H 3 ) 2 , and (d) C s staggered, Cu + – ( N H 3 ) 2 . FIG. 2. Photoionization efficiency spectra of Cu ( N H 3 ) 2 (a) and Cu ( N D 3 ) 2 (b) seeded in He carrier gas. FIG. 3. ZEKE spectra of Cu ( N H 3 ) 2 (a) and Cu ( N D 3 ) 2 (b) in He carrier. FIG. 4. Experimental spectrum (a) and simulation of doubly D 3 d (b) and singly C s (c) bound isomers of Cu ( N H 3 ) 2 .

ASJC Scopus subject areas

  • Physics and Astronomy (all)
  • Physical and Theoretical Chemistry

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