catena-Poly[[[bis(N,N-dimethylformamide)iron(II)]-{μ-2,2′-bis(diphenylphosphinoyl)-N,N′-[(1R,2R)-cyclohexane-1,2-diyl]dibenzamide}] bis(perchlorate) N,N-dimethylformamide disolvate]

The title extended solid coordination compound, {[Fe(C44H40N2O4P2)(C3H7NO)2](ClO4)2·2C3H7NO}n, was crystallized unexpectedly from the reaction mixture containing the Trost ligand (1R,2R)-(+)-1,2-diaminocyclohexane-N,N′-bis(2′-diphenylphosphinobenzoyl) and Fe(ClO4)2·6H2O in a 1:1 ratio in dimethylformamide (DMF) under reflux conditions. The polymeric complex is characterized by FeII metal centers that are coordinated by two oxidized Trost ligands, each coordinated in a bidentate fashion in a square plane, along with two DMF molecules above and below the plane [average Fe—ODMF = 2.086 (4) Å], forming an overall pseudo-octahedral geometry. The Trost ligand binds adjacent FeII centers, each FeII being bound through the O atom of one of the phosphine oxides [average Fe—OPPh2 = 2.115 (4) Å] and the carbonyl O atom of the adjacent amide [average Fe—Oamide = 2.192 (3) Å]. Disorder is observed in the co-solvated solvent: there are two DMF molecules per FeII centre, which were modeled as one DMF molecule with complete occupancy and the other being modeled in two positions with equal occupancy. Disorder was also observed with one of the perchlorate anions, which was modeled in two positions with 0.75:0.25 occupancy.

The title extended solid coordination compound, {[Fe(C 44 H 40 -N 2 O 4 P 2 )(C 3 H 7 NO) 2 ](ClO 4 ) 2 Á2C 3 H 7 NO} n , was crystallized unexpectedly from the reaction mixture containing the Trost ligand (1R,2R)-(+)-1,2-diaminocyclohexane-N,N 0 -bis(2 0 -diphenylphosphinobenzoyl) and Fe(ClO 4 ) 2 Á6H 2 O in a 1:1 ratio in dimethylformamide (DMF) under reflux conditions. The polymeric complex is characterized by Fe II metal centers that are coordinated by two oxidized Trost ligands, each coordinated in a bidentate fashion in a square plane, along with two DMF molecules above and below the plane [average Fe-O DMF = 2.086 (4) Å ], forming an overall pseudo-octahedral geometry. The Trost ligand binds adjacent Fe II centers, each Fe II being bound through the O atom of one of the phosphine oxides [average Fe-O PPh2 = 2.115 (4) Å ] and the carbonyl O atom of the adjacent amide [average Fe-O amide = 2.192 (3) Å ]. Disorder is observed in the co-solvated solvent: there are two DMF molecules per Fe II centre, which were modeled as one DMF molecule with complete occupancy and the other being modeled in two positions with equal occupancy. Disorder was also observed with one of the perchlorate anions, which was modeled in two positions with 0.75:0.25 occupancy.

Experimental
Crystal data [Fe(C 44

S1. Comment
In the course of examining metal-amidato systems, we reacted the Trost ligand (1R,2R)-(+)-1,2-diaminocyclohexane-N, N′-bis(2′-diphenylphosphinobenzoyl) with Fe(ClO 4 ) 2 .6H 2 O in order to form the tetracoordinated Fe II complex using similar conditions reported by Wong (Gao et al., 1996) for the analogous Ru II complex ( Figure 1). Using Fe(ClO 4 ) 2 .6H 2 O as the metal salt and DMF as the solvent, a pale brown solid was obtained which was recrystallized for x-ray analysis.
The structure of the extended cation of 2DMF] x is shown in Figure 2. It is noted that adventitious water and/or oxygen oxidized the phosphine moieties. Only one isomer of the product was observed; where two oxidized Trost ligands (phosphine oxides) adopt a trans-coordination geometry with respect to each other, and two DMF molecules binding to the apical sites forming an octahedral Fe II complex ( Figure 3).  et al., 1971;Müller et al., 1989), including those in the title structure (Fe-O DMF : 2.084 (4) and 2.087 (4) Å). Disorder was observed solely from the co-solvated DMF molecules and one of the perchlorate anions (see Figure 3). The co-solvated DMF was modeled with one molecule at 100% occupancy and the other modeled at two positions (DMF's containing N3s and N4s) with 50:50 occupancy. Bond distances of one DMF molecule were restrained owing to unmodelable disorder. The disordered perchlorate ion (containing Cl2) was modeled in two positions with 75:25 occupancy and some of the thermal parameters were restrained to be similar to each other because of NPD's.

S2. Experimental
To a 100 ml sidearm flask containing a stirbar and ligand (1R,2R)-(+)- h. The solution was cooled to room temperature and the solution was filtered into another sidearm flask. The filtrate solvent was removed under reduced pressure leaving a resulting brown solid (mass) that was transferred to the glovebox for storage. The solid (20 mg) was dissolved in minimal DMF (dried via SPS), filtered to remove any undissolved particles, and placed in a 1 dram vial. The vial was placed in a 3 dram vial containing diethyl ether (dried via SPS) and the 3 dram vial was sealed to allow vapor diffusion crystallization to occur. After 2 days, oval crystals of the title complex precipitated and one was characterized by x-ray crystallography.

S3. Refinement
Owing to unmodelable disorder, the bond distances on one of the co-solvated molecules of DMF was restrained.
Furthermore, one of the co-solvated DMF molecules was disordered 75:25. One of the perchlorates was disordered 50:50 and some of the thermal parameters were restrained to be similar to each other because of NPD's.

Figure 1
Reported synthesis of a neutral Ru II complex containing an achiral aliphatic Trost ligand analogue.   Thermal ellipsoids are drawn at 30% probability.

cyclohexane-1,2-diyl]dibenzamide}] bis(perchlorate) N,N-dimethylformamide disolvate]
Crystal data [Fe(C 44 (2) Special details Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'s involving l.s. planes. Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > 2σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.