Nitrosylbromokomplexe des Rheniums: Re(NO)₂Br₃ und [Re(NO)₂Br₄]^⊖; die Kristallstruktur von PPh₄[Re(NO)₂Br₄] · 2 CCl₄

Abstract

PPh4[Re(NO)2Br4] entsteht als dunkelrotbraunes Pulver aus PPh4[Re(NO)2Cl4] mit überschüssigem Bortribromid. Aus Lösungen von CH2Br2 und CCl4 kristallisiert es unter Einschluß von zwei Mol CCl4, von denen i. Vak. eines leicht abgegeben wird. Mit Aluminiumtribromid läßt sich aus [Re(NO)2Br4]⊖ in CH2Br2‐Lösung ein Bromidligand abspalten, wobei Re(NO)2Br3 als schwerlösliches, rotbraunes Pulver ausfällt. Die IR‐Spektren ergeben Aufschluß über cis‐ständige Nitrosylliganden, die kovalent an Rhenium gebunden sind. Re(NO)2Br3 ist über Bromobrücken dimerisiert. Die Kristallstruktur von PPh4[Re(NO)2Br4] · 2 CCl4 wurde mittels Röntgenbeugung bei − 115°C ermittelt. Der Komplex kristallisiert in der monoklinen Raumgruppe P21/c mit vier Formeleinheiten pro Elementarzelle (4434 unabhängige Reflexe, R = 0,085) und mit den Gitterabmessungen a = 1 092,3 pm, b = 2 088,0 pm, c = 1 657,6 pm und β = 96,10°. Die Struktur besteht aus P(C6H5)4⊖‐Kationen, [Re(NO)2Br4]⊖‐Anionen und eingelagerten CCl4‐Molekülen. In den komplexen Anionen sind die Nitrosylliganden in gestreckter Koordination und in cis‐Stellung zueinander orientiert.

Crystal structure and magnetic study of the complex salt [RuCp(PTA)2–μ-CN-1κC:2κN–RuCp(PTA)2][Re(NO)Br4(EtOH)0.5(MeOH)0.5]

“…In all of them, the rhenium coordination sphere exhibits an octahedral geometry, with a practically lineal {Re-NO} unit and a -acceptor ligand such as phosphine or aromatic amines, usually coordinating trans-to the -NO group. The found -acceptor ligands include: MeCN (Ciani et al, 1975), EtOH (Ciani et al, 1975, pyrazine (Pacheco et al, 2013(Pacheco et al, , 2014, nitrosyl (Mronga et al, 1982), tricyclohexylphosphine and triisopropylphosphine (Jiang et al, 2010), nicotinic acid and nicotinate anion (Pacheco, Cuevas, Gonzá lez-Platas, Lloret et al, 2015), pyridine, pyrimidine and pyridazine (Pacheco et al, 2013). All Re-Br distances observed in the complex reported herein, as well as the Re-N and N-O distances found, agree with those found for previously reported structures (see Figs.…”

Dihalomethanes as Bent Bifunctional XB/XB‐Donating Building Blocks for Construction of Metal‐involving Halogen Bonded Hexagons

“…In two cases, hexagon-like moieties are not linked to the chains and stay as separated units (Figure S30, S32). [13] LICKAM CBr 4 0.86-0.87 [PtCl 2 (NCNEt 2 ) 2 ] [13] LICKIU CBr 4 0.92-0.98 [PdCl 2 (NCNMe 2 ) 2 ] [13] LIHMATC HBr 3 0.91 [PdCl 2 (NCNMe 2 ) 2 ] [13] LIHMEXC HI 3 0.89-0.90 [PtCl 2 (NCNMe 2 ) 2 ] [13] LIHMIBCHBr 3 0.92 [PtCl 2 (NCNCH(CH 2 ) 3 CH) 2 ] [20] UKAWOU CHI 3 0.87-0.89 [PtCl 2 (NCNMe 2 ) 2 ] [20] UKEKIG CHI 3 0.89-0.91 [PtBr 2 (NCNMe 2 ) 2 ] [20] UKELAZ CHI 3 0.89-0.90 [PtCl 2 (NCNEt 2 ) 2 ] [20] UKELEDC HI 3 0.87-0.94 [PPh 4 ][ReBr 4 (NO) 2 ] [21] BOJFOV CCl 4 0.95-0.99 [PdCl 2 (P(OC 12 H 8 O)OPh)] 2 [22] EJOHAN CHCl 3 0.97-0.99 [AsPh 4 ][W 2 Cl 2 (N 3 S 2 ) 3 ] [23] FEPVURCCl 4 0.98 [PtCl 2 (NHC(Et)(C 3 N 2 H 3 )] [24] MEHZAB CHCl 3 0.89-0.96 [SiBr 2 (OC(Ph)NHNC(Me) 2 ] [25] UFOYETCHCl 3 0.97-0.99 [NPr 4 ][CuBr 2 ] [26] HIGRAR CBr 4 0.85-0.91…”

Noncovalent Interactions under Extreme Conditions: High-Pressure and Low-Temperature Diffraction Studies of the Isostructural Metal−Organic Networks (4-Chloropyridinium)2[CoX4] (X = Cl, Br)

“…Thus, we have nearly reached the lower limit observed for such interactions by applying pressure without having a phase transition. The three shortest M−Br···Cl−C halogen bonds found in the CSD are 3.336 Å (QEVFOM, M = Ni), 3.348 Å (BOJFOV, M = Re), and 3.371 Å (TEFWOQ, M = Co). When a pressure of 3.73 GPa is applied to compound 2 , an M−Br···Cl−C distance of 3.261 Å is observed, which is the shortest of the M−Br···Cl−C halogen bonds reported to date at room temperature.…”