MEASUREMENT OF HYPERFINE STRUCTURE AND PERMANENT ELECTRIC DIPOLE MOMENTS IN THE ELECTRONIC SPECTRUM OF IRIDIUM MONOHYDRIDE AND DEUTERIDE C. LINTON, A. D. GRANGER, A. G. ADAM University of New Brunswick S. E. FREY, A. LE, T. C. STEIMLE Arizona State University

2 %AbundanceIμNμN gNgN Q (Barns) 191 Ir373/ Ir633/ H1H~1001/ _ 2D2D? Co1007/ ,193 Ir quadrupole interaction relatively large. UNB 2010: Pulse laser excitation of five Ω = transitions of IrH and IrD. Analyzed rotational structure. Ground state X 3 Φ 4 ASU 2011: High resolution spectra of transitions of IrH at cm -1 and IrD at cm -1 to measure hyperfine structure and dipole moment

IrH R(4) Q(4) P(5) R(4) Q(4) P(5) 193 IrH 191 IrH

IrD R(4) Q(4) P(5) R(4) Q(4) P(5) 193 IrD 191 IrD

193 IrD Q(4) ΔF = 0 : F” = ; 5.5 ΔF = -1: F” = ΔF = +1:F” = ;4.5

Hyperfine energy W = W mag + W quad Hyperfine Analysis C = [F(F+1) – J(J+1) – I(I+1)] h 4 = aΛ + (b F +2c/3)Σ = 3a + (b F +2c/3)

ParameterGroundUpper (cm -1 ) 193 IrD 191 IrD 193 IrD 191 IrD T0T (26) (34) B (10) (20) (10) (20) D1.53(21) (27) (21) (27) h4h (30) (30) (20) (40) eQq (11) (15) (10) (16) h 4 (193/191)1.05(~1.09 a )1.07(~1.09 a ) eQq 0 (193/191)0.98(~0.92 b )1.03(~0.92 b ) Std. dev = cm -1 ( 193 IrD) and cm -1 ( 191 IrD) Parameters for the [18.2] 3  4 - X 3  4 band of 193 IrD and 191 IrD From fit to R(4), R(5), Q(4), Q(5), Q(6), P(5), P(6) a.Ratio of magnetic moments between 193 Ir and 191 Ir b.Ratio of electric quadrupole moments between 193 Ir and 191 Ir

193 IrD R(4) Observed and Calculated (F’ F”) ( ) ( ) ( ) ( ) ( )

193 IrD Q(4) Observed and Calculated ΔF=0 : F”= ; 5.5

193 IrD P(5) Observed and Calculated (F’ F”) ( ) ( ) ( : )

Ground X 3 Φ 4 State in CoF and IrF was found to be a mixture of two configurations A: Ir + (5d 8 ) + F - (2p 6 ) → (5dσ) 2 (5dπ) 3 (5dδ) 3 (2 open shells) B : Ir + (5d 7 6s 1 ) + F - (2p 6 ) → (5dσ) 1 (5dπ) 3 (5dδ) 3 (6sσ) 1 (4 open shells) CoFCoHIrFIrD h4h eQq Comparison of Hyperfine Parameters Ground X 3 Φ 4 State of CoH: covalent primarily with 2 open shells A: Co(3d 8 4s)+H(1s) →(1s+4s, σ) 2 (3dσ) 2 (3dπ) 3 (3dδ) 3 Small contribution from 4 open shell B: Co(3d 7 4s 2 )+H(1s) → (1s+4s, σ) 2 (3dσ) 1 (3dπ) 3 (3dδ) 3 (4sσ) 1 h 4 suggest greater contribution from 4 open shell config n

193 IrH P(5) Stark parallel Field (V/cm) F’ F”

193 IrH P(5) Stark Perpendicular Field (V/cm)

The Stark shifts (first-order perturbation theory H=-μE Stark Analysis Level Spacing MFMF MFMF M F -1 M F +1 Δ M F = Separation of ΔM F = +1 and -1 = 2 ΔW ΔW=E MF+1 - E MF is the same in both states Upper State: Ω = 4 J = 4 F = 2.5 Lower State: Ω = 4 J = 5 F = 3.5

CoFCoHIrFIrH μ(D) R e (A) μ/Re(D/A) Charge0.54e0.26e0.31e0.16e ED a Comparative Ground State Dipole Moment Data a. ED = Electronegativity Difference (Pauling scale) Dipole moment data consistent with electronegativity difference

Conclusions Ir hyperfine structure resolved for IrH and IrD Obtained magnetic and quadrupole hyperfine parameters of IrD 4 open shell ground state σπ 3 δ 3 σ configuration from Ir(d 7 s) considerably more significant in IrH than CoH Ground state dipole moment of IrH (1.23D) shows bonding is mainly covalent consistent with electronegativity difference