Reaction of the unidentate pyridine ligand containing a bulky t-butyl substituent with Fe2+ and [Au(CN)2] affords a new type of spin crossover (SCO) coordination polymer in the 1D compound [Fe(4-tBupy)3][Au(CN)2]2⋅0.5H2O (1), which is formed by chains of Fe(II) complexes linked through bridging [Au(CN)2] with three terminal 4-tBupy and one monodentate [Au(CN)2] ligands completing the octahedral coordination around Fe(II). Longer reaction times led to the minor products [Fe(4-tBupy)2][Au(CN)2]2 (2), which presents a 2D structure more similar to that found in the other SCO compounds based on [Au(CN)2], and the 1D compound [Fe(4-tBupy)2(MeOH)][Au(CN)2]2 (3), in which one of the three terminal 4-tBupy found in 1 is replaced by a coordinating MeOH molecule. Magnetic measurements of 1 show an abrupt spin transition with the temperature with hysteresis and light-induced excited spin-state trapping effect. Structural analysis of 2 and 3 indicates that Fe(II) remains in the high-spin state in these compounds.

1.
See for general reviews
, (a) “
Spin crossover in transition metal compounds
,” in
Topics in Current Chemistry
, edited by
P.
Gütlich
and
H. A.
Goodwin
(
Springer Verlag
,
Berlin
,
2004
),
Vols. 233–235
; (
b
) in
Spin-Crossover Materials: Properties and Applications
, edited by
M. A.
Halcrow
(
John Wiley & Sons
,
Chichester
,
2013
)
2.
K.
Senthil Kumar
and
M.
Ruben
,
Coord. Chem. Rev.
346
,
176
(
2017
).
3.
G.
Molnár
,
S.
Rat
,
L.
Salmon
,
W.
Nicolazzi
, and
A.
Bousseksou
,
Adv. Mater.
30
,
1703862
(
2018
).
4.
A.
Enriquez-Cabrera
,
A.
Rapakousiou
,
M.
Piedrahita Bello
,
G.
Molnár
,
L.
Salmon
, and
A.
Bousseksou
,
Coord. Chem. Rev.
419
,
213396
(
2020
).
5.
Z.-P.
Ni
,
J.-L.
Liu
,
M. N.
Hoque
,
W.
Liu
,
J.-Y.
Li
,
Y.-C.
Chen
, and
M.-L.
Tong
,
Coord. Chem. Rev.
335
,
28
(
2017
).
6.
K.
Otsubo
,
T.
Haraguchi
, and
H.
Kitagawa
,
Coord. Chem. Rev.
346
,
123
(
2017
).
7.
M.
Meneses-Sánchez
,
L.
Piñeiro-López
,
T.
Delgado
,
C.
Bartual-Murgui
,
M. C.
Muñoz
,
P.
Chakraborty
, and
J. A.
Real
,
J. Mater. Chem. C
8
,
1623
(
2020
).
8.
M. C.
Muñoz
and
J. A.
Real
,
Coord. Chem. Rev.
255
,
2068
(
2011
).
9.
L.
Piñeiro-López
,
F. J.
Valverde-Muñoz
,
M.
Seredyuk
,
C.
Bartual-Murgui
,
M. C.
Muñoz
, and
J. A.
Real
,
Eur. J. Inorg. Chem.
2018
,
289
(
2018
).
10.
M. C.
Muñoz
,
A. B.
Gaspar
,
A.
Galet
, and
J. A.
Real
,
Inorg. Chem.
46
,
8182
(
2007
).
11.
A.
Galet
,
M. C.
Muñoz
,
V.
Martínez
, and
J. A.
Real
,
Chem. Commun.
2004
,
2268
(
2004
).
12.
A.
Galet
,
M. C.
Muñoz
,
A. B.
Gaspar
, and
J. A.
Real
,
Inorg. Chem.
44
,
8749
(
2005
).
13.
T.
Kosone
,
I.
Tomori
,
C.
Kanadani
,
T.
Saito
,
T.
Mochida
, and
T.
Kitazawa
,
Dalton Trans.
39
,
1719
(
2010
).
14.
K.
Kitase
and
T.
Kitazawa
,
Dalton Trans.
49
,
12210
(
2020
).
15.
M.
Seredyuk
,
A. B.
Gaspar
,
V.
Ksenofontov
,
M.
Verdaguer
,
F.
Villain
, and
P.
Gütlich
,
Inorg. Chem.
48
,
6130
(
2009
).
16.
G.
Agustí
,
A. B.
Gaspar
,
M. C.
Muñoz
,
P. G.
Lacroix
, and
J. A.
Real
,
Aust. J. Chem.
62
,
1155
(
2009
).
17.
S.
Yurdakul
and
M.
Bahat
,
J. Mol. Struct.
412
,
97
(
1997
).
18.
G. M.
Sheldrick
,
Acta Crystallogr.
A71
,
3
(
2015
).
19.
G. M.
Sheldrick
,
Acta Crystallogr.
C71
,
3
(
2015
).
20.
O. V.
Dolomanov
,
L. J.
Bourhis
,
R. J.
Gildea
,
J. A. K.
Howard
, and
H.
Puschmann
,
J. Appl. Crystallogr.
42
,
339
(
2009
).
21.
V.
García-López
,
M.
Palacios-Corella
,
S.
Cardona-Serra
,
M.
Clemente-León
, and
E.
Coronado
,
Chem. Commun.
55
,
12227
(
2019
).
22.
M.
Ahmed
,
Z.
Xie
,
S.
Thoonen
,
C.
Hua
,
C. J.
Kepert
,
J. R.
Price
, and
S. M.
Neville
,
Chem. Commun.
57
,
85
(
2021
).
23.
A.
Galet
,
M. C.
Muñoz
, and
J. A.
Real
,
Chem. Commun.
2006
,
4321
(
2006
).
24.
J. E.
Clements
,
J. R.
Price
,
S. M.
Neville
, and
C. J.
Kepert
,
Angew. Chem. Int. Ed.
55
,
15105
(
2016
).
25.
L.
Piñeiro-Loṕez
,
F. J.
Valverde-Muñoz
,
M.
Seredyuk
,
M. C.
Muñoz
,
M.
Haukka
, and
J. A.
Real
,
Inorg. Chem.
56
,
7038
(
2017
).
26.
T.
Delgado
,
M.
Meneses-Sánchez
,
L.
Piñeiro-López
,
C.
Bartual-Murgui
,
M. C.
Muñoz
, and
J. A.
Real
,
Chem. Sci.
9
,
8446
(
2018
).
27.
Preliminary single crystal x-ray diffraction studies of 2 and 3 from 120 to 300 K show Fe—N distances consistent with the HS state of Fe(II).

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