TY - JOUR
T1 - Isomeric Forms of Heavier Main Group Hydrides: Experimental and Theoretical Studies of the [Sn(Ar)H]2 (Ar = Terphenyl) System.
AU - Rivard, Eric
AU - Fischer, Roland C.
AU - Wolf, Robert
AU - Peng, Yang
AU - Merrill, W. Alexander
AU - Schley, Nathan D.
AU - Zhu, Zhongliang
AU - Pu, Lihung
AU - Fettinger, James C.
AU - Teat, Simon J.
AU - Nowik, Isreal
AU - Herber, Rolfe H.
AU - Takagi, Nozomi
AU - Nagase, Shigeru
AU - Power, Philip P.
N1 - M1 - Copyright (C) 2017 American Chemical Society (ACS). All Rights Reserved.
CAPLUS AN 2007:1384920(Journal)
PY - 2007
Y1 - 2007
N2 - A series of sym. divalent Sn(II) hydrides of the general form [(4-X-Ar')Sn(μ-H)]2 (4-X-Ar' = C6H2-4-X-2,6-(C6H3-2,6-iPr2)2; X = H, MeO, tBu, and SiMe3; 2, 6, 10, and 14), along with the more hindered asym. tin hydride (3,5-iPr2-Ar*)SnSn(H)2(3,5-iPr2-Ar*) (16) (3,5-iPr2-Ar* = 3,5-iPr2-C6H-2,6-(C6H2-2,4,6-iPr3)2), have been isolated and characterized. They were prepd. either by direct redn. of the corresponding aryltin(II) chloride precursors, ArSnCl, with LiBH4 or iBu2AlH (DIBAL), or via a transmetalation reaction between an aryltin(II) amide, ArSnNMe2, and BH3·THF. Compds. 2, 6, 10, and 14 were obtained as orange solids and have centrosym. dimeric structures in the solid state with long Sn···Sn sepns. of 3.05 to 3.13 Å. The more hindered tin(II) hydride 16 crystd. as a deep-blue solid with an unusual, formally mixed-valent structure wherein a long Sn-Sn bond is present [Sn-Sn = 2.9157(10) Å] and two hydrogen atoms are bound to one of the tin atoms. The Sn-H hydrogen atoms in 16 could not be located by x-ray crystallog., but complementary Moessbauer studies established the presence of divalent and tetravalent tin centers in 16. Spectroscopic studies (IR, UV-vis, and NMR) show that, in soln., compds. 2, 6, 10, and 14 are predominantly dimeric with Sn-H-Sn bridges. In contrast, the more hindered hydrides 16 and previously reported (Ar*SnH)2 (17) (Ar* = C6H3-2,6-(C6H2-2,4,6-iPr3)2) adopt primarily the unsym. structure ArSnSn(H)2Ar in soln. Detailed theor. calcns. have been performed which include calcd. UV-vis and IR spectra of various possible isomers of the reported hydrides and relevant model species. These showed that increased steric hindrance favors the asym. form ArSnSn(H)2Ar relative to the centrosym. isomer [ArSn(μ-H)]2 as a result of the widening of the interligand angles at tin, which lowers steric repulsion between the terphenyl ligands. [on SciFinder(R)]
AB - A series of sym. divalent Sn(II) hydrides of the general form [(4-X-Ar')Sn(μ-H)]2 (4-X-Ar' = C6H2-4-X-2,6-(C6H3-2,6-iPr2)2; X = H, MeO, tBu, and SiMe3; 2, 6, 10, and 14), along with the more hindered asym. tin hydride (3,5-iPr2-Ar*)SnSn(H)2(3,5-iPr2-Ar*) (16) (3,5-iPr2-Ar* = 3,5-iPr2-C6H-2,6-(C6H2-2,4,6-iPr3)2), have been isolated and characterized. They were prepd. either by direct redn. of the corresponding aryltin(II) chloride precursors, ArSnCl, with LiBH4 or iBu2AlH (DIBAL), or via a transmetalation reaction between an aryltin(II) amide, ArSnNMe2, and BH3·THF. Compds. 2, 6, 10, and 14 were obtained as orange solids and have centrosym. dimeric structures in the solid state with long Sn···Sn sepns. of 3.05 to 3.13 Å. The more hindered tin(II) hydride 16 crystd. as a deep-blue solid with an unusual, formally mixed-valent structure wherein a long Sn-Sn bond is present [Sn-Sn = 2.9157(10) Å] and two hydrogen atoms are bound to one of the tin atoms. The Sn-H hydrogen atoms in 16 could not be located by x-ray crystallog., but complementary Moessbauer studies established the presence of divalent and tetravalent tin centers in 16. Spectroscopic studies (IR, UV-vis, and NMR) show that, in soln., compds. 2, 6, 10, and 14 are predominantly dimeric with Sn-H-Sn bridges. In contrast, the more hindered hydrides 16 and previously reported (Ar*SnH)2 (17) (Ar* = C6H3-2,6-(C6H2-2,4,6-iPr3)2) adopt primarily the unsym. structure ArSnSn(H)2Ar in soln. Detailed theor. calcns. have been performed which include calcd. UV-vis and IR spectra of various possible isomers of the reported hydrides and relevant model species. These showed that increased steric hindrance favors the asym. form ArSnSn(H)2Ar relative to the centrosym. isomer [ArSn(μ-H)]2 as a result of the widening of the interligand angles at tin, which lowers steric repulsion between the terphenyl ligands. [on SciFinder(R)]
KW - isomeric heavier main group divalent terphenyl tin hydride prepn
KW - crystal mol structure sterically crowded aryl tin hydride
U2 - 10.1021/ja076453m
DO - 10.1021/ja076453m
M3 - Article
SN - 0002-7863
VL - 129
SP - 16197
EP - 16208
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 51
ER -