(N→B)-4-Methyl-3-pyridyl[N-methyliminodiacetate-O,O′,N]borane

The title compound, C11H13BN2O4, has a rigid bicyclic structure due to an intramolecular nitrogen–boron dative bond. The B atom is in a distorted tetrahedron environment with a B—N bond length of 1.640 (2) Å, which is in good comparison with the values in analogues compounds. In the crystal, the molecules are linked by weak C—H⋯O and C—H⋯N interactions, forming a three-dimensional network.

The title compound, C 11 H 13 BN 2 O 4 , has a rigid bicyclic structure due to an intramolecular nitrogen-boron dative bond. The B atom is in a distorted tetrahedron environment with a B-N bond length of 1.640 (2) Å , which is in good comparison with the values in analogues compounds. In the crystal, the molecules are linked by weak C-HÁ Á ÁO and C-HÁ Á ÁN interactions, forming a three-dimensional network.
Data collection: CrysAlis PRO (Agilent, 2011); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL; molecular graphics: DIAMOND (Brandenburg, 2005); software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009). The X-ray measurements were undertaken in the Crystallographic Unit of the Physical Chemistry Laboratory at the Chemistry Department of the University of Warsaw. This work was supported by the Aldrich Chemical Co. through donation of chemicals and equipment and by the Warsaw University of Technology.  (Mancilla et al., 1997(Mancilla et al., , 2005Gillis et al., 2008;Knapp et al., 2009;Percino et al., 2009). Our interest has focused on the MIDA esters of pyridineboronic acids and their structural behavior.
In the title compound, the boron atom has a tetrahedral geometry with bond angles at the B atom ranging from 99.1 (2) to 116.8 (1)°. The B-O [1.466 (2) and 1.489 (2) Å] and B-C [1.595 (2) Å] bond lengths are in the normal ranges for such compounds. The B-N bond length is equal to 1.640 (2) Å and is similar to the values found in the other structures of MIDA boronate esters. As indicated by the C1-B1-N2-C11 and C2-C2-B1-O1 torsion angles, the bicycle ring is significantly distorted and the aryl unit is twisted along C-B bond. The crystal structure is dominated by weak C-H···O and C-H···N hydrogen interactions (Table 1).

Experimental
The title compound was received from Aldrich. Single crystals suitable for X-ray diffraction analysis were grown by cooling a solution of the ester (0.2 g) in diethyl ether (10 ml) and dimethyl sulfoxide (5 ml).

Refinement
All H atoms were placed in calculated positions with C-H distances of 0.95 Å (phenyl), 0.98 Å (methyl) and 0.99 Å (methylene). They were located in difference maps and were included in the refinement in riding approximation with U iso (phenyl and methylene H) = 1.2U eq (C) and U iso (methyl H) = 1.5U eq (C).

Computing details
Data collection: CrysAlis PRO (Agilent, 2011); cell refinement: CrysAlis PRO (Agilent, 2011); data reduction: CrysAlis PRO (Agilent, 2011); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2005); software used to prepare material for publication: SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009   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 > σ(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.