Supporting information for: Spin-State Effects on the
Thermal Dihydrogen Release from Solid-State
[MH(
η
2
-
H
2
)dppe
2
]
+
(M = Fe, Ru, Os) Organometallic
Complexes for Hydrogen Storage Applications
David G. Abrecht, Jorge A. Muñoz, Hillary L. Smith, and Brent Fultz
∗
W.M. Keck Laboratory, California Institute of Technology, 1200 E. California Blvd, MC 138-78,
Pasadena, CA 91125
E-mail: btf@caltech.edu
∗
To whom correspondence should be addressed
S1
Contents
Figure S.1 Mass Spectrograph of Initial Degassing of [FeH(
η
2
-H
2
)dppe
2
][NTf
2
] . . . S3
Figure S.2 Mass Spectrograph of Hydrogen Cycling onto [FeH(
η
2
-H
2
)dppe
2
][NTf
2
] . S4
Figure S.3 Relaxed structure of singlet [FeHdppe
2
]
+
. . . . . . . . . . . . . . . . . . S5
Figure S.4 Relaxed Structure of Triplet [FeHdppe
2
]
+
. . . . . . . . . . . . . . . . . . S6
Figure S.5 Relaxed Structure of [FeH(
η
2
-H
2
)dppe
2
]
+
. . . . . . . . . . . . . . . . . . S7
Table 1
Calculated Energies of Molecular Fragments . . . . . . . . . . . . . . . . . S8
Table 2
SCS-MP2 Calculated Energies of Molecular Fragments . . . . . . . . . . . S10
S2
0
1.0e-6
2.0e-6
3.0e-6
4.0e-6
5.0e-6
6.0e-6
7.0e-6
8.0e-6
0
10
20
30
40
50
60
70
80
90
100
110
120
130
140
150
Pressure, torr
Mass number, Z/e
-
2.0
14.0
28.0
Figure S.1: Residual mass spectrograph of the initial degassing of as-synthesized [FeH(
η
2
-
H
2
)dppe
2
][NTf
2
] containing N
2
contamination at the binding site. Degassing occurred from the
solid state under vacuum conditions at 393K, and shows the preferential loss of N
2
gas from the
species.
S3
0
1.0e-5
2.0e-5
3.0e-5
4.0e-5
5.0e-5
6.0e-5
7.0e-5
8.0e-5
9.0e-5
1.0e-4
0
10
20
30
40
50
60
70
80
90
100
110
120
130
140
150
Pressure, torr
Mass number, Z/e
-
1
st
cycle
2
nd
cycle
3
rd
cycle
Final cycle
Figure S.2: Residual mass spectrograph of the volatile thermal decomposition products of
[FeH(
η
2
-H
2
)dppe
2
][NTf
2
] during hydrogen cycling at 413 K. Hydrogen gas is the only observed
decomposition product from the material after for all four hydrogenation/dehydrogenation cycles.
S4
Figure S.3: Optimized structure of the singlet state organometallic fragment [FeHdppe
2
]
+
using
the UHF approximation and LANL2DZ-ECP basis sets, showing typical octahedral geometry.
Alkyl and aryl hydrogens have been omitted for clarity.
S5
Figure S.4: Optimized structure of the triplet state organometallic [FeHdppe
2
]
+
using the UHF ap-
proximation and LANL2DZ-ECP basis sets. Structure shows the quasi-square pyramidal structure
observed by Franke,
1
et al. Alkyl and aryl hydrogens have been omitted for clarity.
S6
Figure S.5: Optimized structure of [FeH(
η
2
-H
2
)dppe
2
]
+
using the UHF approximation and
LANL2DZ-ECP basis sets, showing the octahedral geometry observed from x-ray diffraction mea-
surements.
2
Alkyl and aryl hydrogens have been omitted for clarity.
S7