The Improved Synthesis of [Cr(N)(salen)].CH₃NO₂

Nitridocyanometalates of CrV, MnV, and MnVI

“…This is mainly due to the fact that only a limited number of synthetic routes to such species appear to be available. Photolysis of azido chromium(III) and manganese(III) precursors (Arshankov reaction) is the most widely used method . It has also been reported that treatment of Cr(III) and Mn(III) porphinato and N , N ‘-ethylenebis(salicylideneaminato) complexes with either NaOCl or PhIO in the presence of aqueous ammonia yields Cr V ⋮N and Mn V ⋮N species. 3a-c Cr(V) and Mn(V) nitridophthalocyaninato complexes have been obtained from [M III (OH) 2 Pc(2−)] - (M = Cr, Mn) via oxidation in aqueous NH 3 solution with chlorine. 3d,e More recently, an efficient synthesis of Mn V ⋮N species via oxidation of manganese(III) precursors in CH 2 Cl 2 /ammonia solution with N -bromosuccineimide was described …”

Molecular and Electronic Structure of Nitridochromium(V) Complexes with Macrocyclic Amine Ligands

“…Since the discovery that five-coordinate nitridochromium(V) complexes are synthetically readily accessible via photolysis of azidochromium(III) complexes, this class of compounds has received considerable scientific attention. The Arshankov−Poznjak reaction ,2a of [Cr III (salen)(N 3 )]·2H 2 O, where salen represents the ligand N , N ‘-bis(salicylidene)ethylenediamine(2−), produces [Cr V (N)(salen)], a five-coordinate complex as shown in eq 1 The crystal structure of the latter has recently been reported. 2b,c While mechanisticially the photolysis reaction of [Cr(NH 3 ) 5 (N 3 )] 2+ had been studied earlier, , definitive structural proof for the formation of the Cr V ⋮N moiety was established by X-ray crystallographically in 1983 by Groves et al., who reported the structure of [Cr V (N)(ttp)] (ttp = tetratolylporphinate(2−)).…”

“…The Arshankov−Poznjak reaction ,2a of [Cr III (salen)(N 3 )]·2H 2 O, where salen represents the ligand N , N ‘-bis(salicylidene)ethylenediamine(2−), produces [Cr V (N)(salen)], a five-coordinate complex as shown in eq 1 The crystal structure of the latter has recently been reported. 2b,c While mechanisticially the photolysis reaction of [Cr(NH 3 ) 5 (N 3 )] 2+ had been studied earlier, , definitive structural proof for the formation of the Cr V ⋮N moiety was established by X-ray crystallographically in 1983 by Groves et al., who reported the structure of [Cr V (N)(ttp)] (ttp = tetratolylporphinate(2−)). This compound had been synthesized independently by hypochlorite oxidation of the chromium(III) porphyrins in the presence of NH 3 .…”

Synthesis and molecular structure of Cr(salen)(μ-N)RhCl(COD): the first example of a heterobimetallic nitride-bridged complex containing chromium

“…We have recently devised a general route to chromium(V) nitride complexes based on nitrogen transfer from the easily accessible Mn(N)(salen) {salen is 2,2 0 -[ethane-1,2-diylbis(nitrilomethylidyne)]diphenolate} to labile chromium acceptors (Birk & Bendix, 2003;Bendix, 2003;Bendix et al, 2005). Among the chromium(V) nitride complexes which can be prepared by this route is Cr(N)(salen), which previously was only accessible in modest quantities through a cumbersome photolysis of the chromium(III) precursor Cr(N 3 )(salen) (Arshankow & Poznjak, 1981;Bendix et al, 1998). We have found that Cr(N)(salen) reacts directly with [RhCl(COD)] 2 (COD is 1,5cyclooctadiene) to yield the title complex, (I), which is the first example of the Cr N moiety functioning as a ligand towards another metal.…”

“…The two metals are connected by a nearly linear [173.03 (9) ] nitride bridge. The Cr N is elongated from 1.559 (2) Å in Cr(N)(salen) (Bendix et al, 1998;Table 2) to 1.5936 (14) Å in (I). Despite this modest change in bond length, the N-Rh bond of 1.9594 (14) Å is very short for a monodentate nitrogen-donor ligand bonded to Rh I .…”