10.1021/cg201170w.s004
Magnus
T. Johnson
Magnus
T.
Johnson
Zoran Džolić
Zoran
Džolić
Mario Cetina
Mario
Cetina
Ola F. Wendt
Ola F.
Wendt
Lars Öhrström
Lars
Öhrström
Kari Rissanen
Kari
Rissanen
Neutral Organometallic
Halogen Bond Acceptors: Halogen
Bonding in Complexes of PCPPdX (X = Cl, Br, I) with Iodine (I<sub>2</sub>), 1,4-Diiodotetrafluorobenzene (F4DIBz), and 1,4-Diiodooctafluorobutane
(F8DIBu)
American Chemical Society
2015
halogen
F 4DIBz
F 8DIBu form XB complexes
van der Waals radii
XB donors F 4DIBz
F 8DIBu
iodine
F 8DIBu behavior
pincer palladium chloride 1
Neutral Organometallic Halogen Bond Acceptors
XB interactions
2015-12-16 20:39:03
Dataset
https://acs.figshare.com/articles/dataset/Neutral_Organometallic_Halogen_Bond_Acceptors_Halogen_Bonding_in_Complexes_of_PCPPdX_X_Cl_Br_I_with_Iodine_I_sub_2_sub_1_4_Diiodotetrafluorobenzene_F4DIBz_and_1_4_Diiodooctafluorobutane_F8DIBu_/2017818
The behavior of a sterically crowded neutral pincer {2,6-bis[(di-<i>t</i>-butylphosphino)methyl]-phenyl}palladium (PCPPd) halides,
PCPPdX (X = Cl, Br or I), as XB acceptors with strong halogen bond
(XB) donors, iodine (I<sub>2</sub>), 1,4-diiodotetrafluorobenzene
(F4DIBz), and 1,4-diiodooctafluorobutane (F8DIBu) were studied in
the solid state. The co-crystallization experiments afforded high-quality
single crystals of XB complexes PCPPdCl–I<sub>2</sub> (<b>1a</b>), PCPPdBr–I<sub>2</sub> (<b>2a</b>), PCPPdI–I<sub>2</sub> (<b>3a</b>), PCPPdCl–F4DIBz (<b>1b</b>), PCPPdBr–F4DIBz (<b>2b</b>), and PCPPdBr–F8DIBu
(<b>2c</b>). The 1:1 iodine complexes (<b>1a</b>, <b>2a</b>, and <b>3a</b>) all showed a strong halogen bonding
interaction, the reduction of the sum of the van der Waals radii of
halogen to iodine being 24.6 (<b>1a</b>), 23.9 (<b>2a</b>), and 19.4% (<b>3a</b>) with X···I–I
angles of 177, 176, and 179°, respectively. While the pincer
palladium chloride <b>1</b> and bromide <b>2</b> were
crystallographically isomorphous and showed similar XB behavior, the
palladium iodide complex, <b>3</b>, exhibited markedly different
properties, and unlike <b>1</b> and <b>2</b> it does not,
under similar conditions, result in XB complexes with the weaker XB
donors F4DIBz and F8DIBu. The results indicate that PCPPdI is not
nucleophilic enough to have XB interactions with other donors than
iodine. However, the weaker XB donors F4DIBz and F8DIBu form XB complexes
with the chloride <b>1</b> and especially with the bromide <b>2.</b> The prevalence of the halogen bonding with <b>2</b> is probably not only electronic in origin, and it seems to offer
the best balance between electron poorness and steric availability.
The XB interactions with F4DIBz and F8DIBu are much weaker than with
iodine, the reduction of the sum of the van der Waals radii of halogen
to iodine being 13.5, 12.3, and 14.6% with C–I···X
angles between 163 and 179° for <b>1b</b>, <b>2b</b>, and <b>2c</b>, respectively, and results in polymeric (···<b>1</b>···F4DIBz···<b>1</b>···F4DIBz···)<sub><i>n</i></sub>, (···<b>2</b>···F4DIBz···<b>2</b>···F4DIBz···)<sub><i>n</i></sub>, and (···<b>2</b>···F8DIBu···<b>2</b>···F8DIBu···)<i><sub>n</sub></i> one-dimensional zigzag chains in the solid state.