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. ADAMUniversity of New Brunswick

S. E. FREY, A. LE, T. C. STEIMLEArizona State University

2

%Abundance

I μN gN Q (Barns)

191Ir 37 3/2 +0.151 0.1007 0.82

193Ir 63 3/2 +0.164 0.1093 0.75

1H ~100 1/2 +2.793 5.586 _

2D ? 1 +0.857 0.857 +0.0028

59Co 100 7/2 +4.63 1.322 0.41

191,193Ir quadrupole interaction relatively large.

UNB 2010: Pulse laser excitation of five Ω = 4 - 4 transitions of IrH and IrD. Analyzed rotational structure. Ground state X3Φ4

ASU 2011: High resolution spectra of transitions of IrH at 18060 cm-1 and IrD at 18260 cm-1 to measure hyperfine structure and dipole moment

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

17995.44 17995.46 17995.48 17995.50 17995.52 17995.54

wavenumber (cm-1)

18060.82 18060.84 18060.86 18060.88 18060.90

Wavenumber (cm-1)

18126.30 18126.32 18126.34 18126.36 18126.38 18126.40

Wavenumber (cm-1)

R(4)

Q(4)

P(5)

193IrH 191IrH

18238.60 18238.62 18238.64 18238.66 18238.68 18238.70 18238.72

Wavenumber (cm-1)

18204.88 18204.90 18204.92 18204.94 18204.96 18204.98

Wavenumber (cm-1)

18265.14 18265.16 18265.18 18265.20 18265.22 18265.24 18265.26

Wavenumber (cm-1)

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

R(4)

Q(4)

P(5)

193IrD 191IrD

193IrD Q(4)

18238.61 18238.62 18238.63 18238.64 18238.65 18238.66 18238.67 18238.68

Wavenumber (cm=1)

ΔF = 0: F” = 2.5 3.5 4.5 ; 5.5

ΔF = -1: F” = 3.5 4.5 5.5ΔF = +1:F” = 2.5 3.5;4.5

Hyperfine energy W = Wmag + Wquad

Hyperfine Analysis

)(

ChWmag 1J2J

4

1)1(

3

)32)(12)(12(2

)]1()1()1(75.0[),,,(

:),,,(.

2

0

JJJJII

JJIICCFIJf

FIJfeQqWQuad

C = [F(F+1) – J(J+1) – I(I+1)]

h4 = aΛ + (bF+2c/3)Σ = 3a + (bF+2c/3)

Parameter Ground Upper

(cm-1) 193IrD 191IrD 193IrD 191IrD

T0 0 0 18254.9688(26) 18255.0249(34)

B 3.37521(10) 3.37561(20) 2.49671(10) 2.49627(20)

D 1.53(21).10-5 1.63(27).10-5 -3.1289(21).10-3 -3.1361(27).10-3

h4 0.00796(30) 0.00737(30) 0.02045(20) 0.01913(40)

eQq0 -0.0105(11) -0.0107(15) -0.0437(10) -0.0426(16)

h4(193/191) 1.05(~1.09a) 1.07(~1.09a)

eQq0(193/191) 0.98(~0.92b) 1.03(~0.92b)

Std. dev = 0.0008cm-1 (193IrD) and 0.0010cm-1 (191IrD)

Parameters for the [18.2]34 - X34 band of 193IrD and 191IrD

From fit to R(4), R(5), Q(4), Q(5), Q(6), P(5), P(6)

a. Ratio of magnetic moments between 193Ir and 191Irb. Ratio of electric quadrupole moments between 193Ir and 191Ir

193IrD R(4) Observed and Calculated

18265.16 18265.18 18265.20

Calc

Obs

Wavenumber (cm-1)

(F’ F”) (3.5 3.5) (3.5 2.5) (4.5 3.5) (5.5 4.5) (6.5 5.5)

193IrD Q(4) Observed and Calculated

18238.61 18238.62 18238.63 18238.64 18238.65 18238.66 18238.67 18238.68

Calc

Obs

Wavenumber (cm=1)

ΔF=0: F”= 2.5 3.5 4.5 ; 5.5

193IrD P(5) Observed and Calculated

18204.88 18204.90 18204.92

Wavenumber (cm-1)

(F’ F”) (2.5 3.5) (3.5 4.5) (4.5 5.5 : 5.5 6.5)

Ground X3Φ4 State in CoF and IrF was found to be a mixture of two configurationsA: Ir+(5d8) + F-(2p6) → (5dσ)2(5dπ)3(5dδ)3 (2 open shells)B : Ir+(5d76s1) + F-(2p6) → (5dσ)1(5dπ)3(5dδ)3(6sσ)1 (4 open shells)

CoF CoH IrF IrD

h4 0.0325 0.0515 0.00882 0.00796

eQq0 -0.0027 -0.00309 -0.01003 -.0105

Comparison of Hyperfine Parameters

Ground X3Φ4 State of CoH: covalent primarily with 2 open shells A: Co(3d84s)+H(1s) →(1s+4s, σ)2 (3dσ)2(3dπ)3(3dδ)3

Small contribution from 4 open shellB: Co(3d74s2)+H(1s) → (1s+4s, σ)2 (3dσ)1(3dπ)3(3dδ) 3(4sσ)1

h4 suggest greater contribution from 4 open shell confign

193IrH P(5) Stark parallel

0 600 1200

Relative Frequency (MHz)

Field (V/cm)

0

305

916

F’ 2.5 3.5 5.5 4.5F” 3.5 4.5 6.5 5.5

193IrH P(5) Stark Perpendicular

-600 0 600 1200

-1+1M =

Relative Frequency (MHz)

Field (V/cm)

0

305

610

916

1220

)/5034.0()1()1(2

)]1()1()1([μEDMHz

FFJJ

IIJJFFΩW

The Stark shifts (first-order perturbation theory H=-μE

Stark Analysis

Level Spacing

MF

MF

MF-1

MF+1

ΔMF = +1 0 -1

Separation of ΔMF = +1 and -1 = 2 ΔW

ΔW=EMF+1 - EMF is the same in both states

Upper State: Ω = 4 J = 4 F = 2.5

Lower State: Ω = 4 J = 5 F = 3.5

0 500 1000 15000

20

40

60

80

100

120

140slope = 0.11027(94)' = 0.767(7)D" = 1.232(12)D

Sp

littin

g (

MH

z)

Field (Volts/cm)

CoF CoH IrF IrH

μ(D) 4.51 1.88 2.82 1.23

Re(A) 1.7358 1.531 1.897 1.613

μ/Re(D/A) 2.598 1.278 1.487 0.764

Charge 0.54e 0.26e 0.31e 0.16e

EDa 2.100 0.320 1.78 0.00

Comparative Ground State Dipole Moment Data

a. ED = Electronegativity Difference (Pauling scale)

Dipole moment data consistent with electronegativity difference

ConclusionsIr hyperfine structure resolved for IrH and IrD

Obtained magnetic and quadrupole hyperfine parameters of IrD

4 open shell ground state σπ3δ3σ configuration from Ir(d7s) considerably more significant in IrH than CoH

Ground state dipole moment of IrH (1.23D) shows bonding is mainly covalent consistent with electronegativity difference