Aggregation of [(^tBu₃SiS)MX]:  Structures of {[Br₂Fe(μ-SSi^tBu₃)₂FeBr(THF)]Na(THF)₄}_∞, cis-[(THF)FeI]₂(μ-SSi^tBu₃)₂, [(^tBu₃SiS)Fe]₂(μ-SSi^tBu₃)₂, and Comparative Structure and Magnetism Studies of [(^tBu₃SiS)MX]_n (M = Fe, Co, X

Abstract

A convenient synthesis of (t)Bu(3)SiSH and (t)Bu(3)SiSNa(THF)(x)() led to the exploration of "(t)Bu(3)SiSMX" aggregation. The dimer, [((t)Bu(3)SiS)Fe](2)(mu-SSi(t)Bu(3))(2) (1(2)), was formed from [{(Me(3)Si)(2)N}Fe](2)(mu-N(SiMe(3))(2))(2) and the thiol, and its dissolution in THF generated ((t)Bu(3)SiS)(2)Fe(THF)(2) (1-(THF)(2)). Metathetical procedures with the thiolate yielded aggregate precursors [X(2)Fe](mu-SSi(t)Bu(3))(2)[FeX(THF)]Na(THF)(4) (3-X, X = Cl, Br) and cis-[(THF)IFe](2)(mu-SSi(t)Bu(3))(2) (4). Thermal desolvations of 3-Cl, 3-Br and 4 afforded molecular wheels [Fe(mu-X)(mu-SSi(t)Bu(3))](12)(C(6)H(6))(n) (5-FeX, X = Cl, Br) and the ellipse [Fe(mu-I)(mu-SSi(t)Bu(3))](14)(C(6)H(6))(n) (6-FeI). Related metathesis and desolvation sequences led to wheels [Co(mu-Cl)(mu-SSi(t)Bu(3))](12)(C(6)H(6))(n) (5-CoCl) and [Ni(mu-Br)(mu-SSi(t)Bu(3))](12)(C(6)H(6))(n) (5-NiBr). The nickel wheel disproportionated to give, in part, [((t)Bu(3)SiS)Ni](2)(mu-SSi(t)Bu(3))(2) (7), which was also synthesized via salt metathesis. X-ray structural studies of 1(2) revealed a roughly planar Fe(2)S(4) core, while 1-(THF)(2), 3-Br, and 4 possessed simple distorted tetrahedral and edge-shared tetrahedral structures. X-ray structural studies revealed 5-MX (MX = FeCl, FeBr, CoCl, NiBr) to be wheels based on edge-shared tetrahedra, but while the pseudo-D(6)(d) wheels of 5-FeCl, 5-CoCl, and 5-FeBr pack in a body-centered arrangement, those of pseudo-C(6)(v)() 5-NiBr exhibit hexagonal packing and two distinct trans-annular d(Br...Br). Variable-temperature magnetic susceptibility measurements were conducted on 5-FeCl, 5-CoCl, 5-FeBr, and 6-FeI, and the latter three are best construed as weakly antiferromagnetic, while 5-FeCl exhibited modest ferromagnetic coupling. Features suggesting molecular magnetism are most likely affiliated with phase changes at low temperatures.

Linking Two Distinct Layered Networks of Nanosized {Ln18} and {Cu24} Wheels through Isonicotinate Ligands

“…In FJ‐4 , the {Cu 24 } wheel only bridged by I atoms is unprecedented. In contrast to other TM wheels based on edge‐sharing metal tetrahedra,7d,e the {Cu 24 } wheel comprises two different tetrahedra of Cu1N 3 I and Cu2N 2 I 2 through shared vertices. Such a {Cu 24 } wheel with a 12‐ring and corner‐sharing tetrahedra is analogous to zeolite/zeolite‐like open‐frameworks,20 in which the O atoms are usually bi‐ or tricoordinate.…”

SF and SC Activation of SF6 and SF5 Derivatives at Rhodium: Conversion of SF6 into H2S

“…[13] Complex 4 was characterized by NMR spectroscopy and liquid injection field desorption ionization mass spectrometry (LIFDI MS). The 19 F{ 1 H} NMR spectrum shows a multiplet for the fluorido ligand at d = À355.6 ppm, which is a characteristic chemical shift for rhodium fluorido complexes. The 19 F{ 1 H} NMR spectrum shows a multiplet for the fluorido ligand at d = À355.6 ppm, which is a characteristic chemical shift for rhodium fluorido complexes.…”

“…In the 29 Si{ 1 H} NMR spectrum of 8, a broad multiplet for the silicon atom is observed at d = 22.1 ppm. [19] In an extraordinary reaction, complex 1 proved to be highly reactive towards SF 6 . [12] The geometry around the rhodium centers is close to squareplanar.…”

“…The reaction of 1 with the SF 5 substrates was monitored by 31 P, 19 (5) was also present and presumably serves as the resting state after the reaction of 1 with H 2 . [13] Complex 4 was characterized by NMR spectroscopy and liquid injection field desorption ionization mass spectrometry (LIFDI MS).…”

“…Compounds 6 a-c were characterized in solution by NMR spectroscopy and LIFDI MS. The resonances for the bridging fluorido ligands appear in the 19 F{ 1 H} NMR spectra at high field (d = À390.8 ppm for 6 a). (10), Rh2-S1 2.3131(11), S1-C1 1.785 (2), C1-S1-Rh1 112.32 (13), Rh1-S1-Rh2 77.167(15).…”