Structure and Properties of [Cr^IIIF(NCMe)₅](BF₄)₂·MeCN: A Nonaqueous Source of Cr^IIIF²⁺and a Building Block for New Prussian-Blue-Like Magnetic Materials

Abstract

[Cr (III)F(NCMe) 5](BF 4) 2.MeCN ( 1) was synthesized from a prolonged dissolution of [Cr (III)(NCMe) 6](BF 4) 3 in MeCN via fluoride abstraction from BF 4 (-). Complex 1 exhibits a crystal field splitting, Delta o, of 17 470 cm (-1) and is a nonaqueous source of Cr (III)F (2+). The reaction of 1 with (NEt 4) 3[Cr (III)(CN) 6] formed a new Prussian-blue-like magnetic material of (NEt 4) 0.04[Cr (III)F] 1.54[Cr (III)(CN) 6](BF 4) 0.12.0.10(MeCN) ( 2) composition. Complex 2 magnetically orders at a critical temperature, T c, of 85 K and at 2 K exhibits magnetic hysteresis with a coercive field, H cr, of 60 Oe and a remanent magnetization, M rem, of 1880 emuOe/mol.

A Dinucleating Ligand System with Varying Terminal Donors to Mimic Diiron Active Sites

“…In our efforts to obtain doubly-bridged complexes with oxo or hydroxo donors, we also employed Fe II [72] indicating the hydrolysis of BF 4 À , which is a known reactivity. [73,74] Surprisingly, reacting susan Me with Fe (BF 4 ) 2 • 6H 2 O under the same aerobic conditions provided the (Figure 3b). [48] Using anaerobic conditions, the bis-μ-fluorobridged Fe II Fe II complex [(susan Me ){Fe(μ-F) 2 Fe}](BF 4 ) 2 was obtained ( Figure 3c).…”

“…In our efforts to obtain doubly‐bridged complexes with oxo or hydroxo donors, we also employed Fe II (BF 4 ) 2 ⋅ 6H 2 O as Fe II source. Under aerobic basic conditions, using the ligand susan we obtained the mono‐ μ ‐oxo‐bridged complex [(susan){FeF( μ ‐O)FeF}](BF 4 ) 2 with terminal fluoro ligands (Figure 3a) [72] indicating the hydrolysis of BF 4 − , which is a known reactivity [73,74] . Surprisingly, reacting susan Me with Fe(BF 4 ) 2 ⋅ 6H 2 O under the same aerobic conditions provided the μ ‐fluoro‐bridged mixed‐valent Fe II Fe III complex [(susan Me ){Fe II F( μ ‐F)Fe III F}](BF 4 ) 2 as the first iron complex of susan Me (Figure 3b) [48] .…”

Synthesis and Reactivity of Low-Coordinate Titanium Synthons Supported by a Reduced Redox-Active Ligand

“…Single-crystal X-ray diffraction studies of 3 and 4 were carried out at 200(2) K and 100(2) K, respectively, following previously described protocols. 19 For complex 3, the crystal-to-detector distance was 30 mm and the exposure time was 5 s per frame using a scan width of 0.75°. The crystal-todetector distance was 60 mm and the exposure time was 1 s per frame using a scan width of 0.5°in the case of 4.…”

One Electron Changes Everything: Synthesis, Characterization, and Reactivity Studies of [Re(NCCH3)6]3+

“…The band assignment was performed as in the case of uncoordinated CH 3 CN . Similar IR spectrum patterns are reported for [ 99 Tc­(NCCH 3 ) 6 ]­(BF 4 ) 2 as well as for various first-row transition-metal analogues. , No fluoride abstraction from BF 4 – as found in [Cr­(NCCH 3 ) 6 ]­(BF 4 ) 3 was observed for [ 2b ]­(BF 4 ) 3 when dissolved in CH 3 CN over prolonged periods of time . [ 2b ]­(BF 4 ) 3 is unstable under a normal atmosphere (O 2 and moisture) and decomposes within minutes even as a solid, if not protected by, for example, an oil such as “Infineum V8512” used for X-ray diffraction analysis.…”

“…7,18 No fluoride abstraction from BF 4 − as found in [Cr-(NCCH 3 ) 6 ](BF 4 ) 3 was observed for [2b](BF 4 ) 3 when dissolved in CH 3 CN over prolonged periods of time. 19 [2b](BF 4 ) 3 is unstable under a normal atmosphere (O 2 and moisture) and decomposes within minutes even as a solid, if not protected by, for example, an oil such as "Infineum V8512" used for X-ray diffraction analysis. An assessment of the 16,20 Even though the structures of [2b] 3+ and its reduced analogue [2a] 2+ are very similar, their respective reactivities differ distinctly.…”