( N , N ′ -Di- tert -butyl- S -phenylsulfinimidamidato- κ N , κ N ′ )- chlorogermanium-κ Ge -chloro( η 2 , η 2 -cycloocta-1,5-diene)rhodium

: The title complex [{PhS( t BuN) 2 }(Cl)Ge: → RhCl(cod)] ( 2 ) was synthesized by the reaction of three-coordinated chlorogermylene, [PhS( t BuN) 2 ]GeCl ( 1 ), supported by a diimidosulfinate ligand with a half equivalent of [RhCl(cod)] 2 in benzene. The molecular structure of 2 was determined by 1 H and 13 C NMR spectroscopies and single-crystal X-ray diffraction (SCXRD) analysis. The electronic property of germylene 1 was assessed by determining the Tolman electronic parameter of the corresponding cis -dicarbonyl Rh(I) complex, [{PhS( t BuN) 2 }(Cl)Ge: → RhCl(CO) 2 ] ( 3 ), that was prepared by the treatment of 2 with carbon monoxide.


Results and Discussion
The treatment of [PhS(tBuN) 2 ]GeCl 1 [33] with a half equivalent of [RhCl(cod)] 2 in benzene gave the corresponding germylene-Rh(I) complex [{PhS(tBuN) 2 }(Cl)Ge: →RhCl(cod)] 2 as an orange powder in a 66% yield (Scheme 1).In the 1 H NMR spectrum of 2, a singlet signal due to tert-butyl groups was observed at 1.34 ppm.Four non-equivalent signals assigned to methylene protons in the cod ligand were found at 1.70-1.78,2.12, and 2.24 ppm.Two alkenyl protons in the cod ligand appeared at 4.23 and 5.62 ppm as a broad signal.Single crystals of 2 suitable for X-ray diffraction analysis were obtained from a saturated benzene solution at room temperature.The ORTEP of 2 is illustrated in Figure 1, and selected bond lengths and bond angles are provided in Table 1.Complex 2 crystallizes in the triclinic space group P-1 with a benzene molecule per unit cell.As depicted in Figure 1, the central rhodium atom, to which the germanium atom is coordinated, and the phenyl group on the sulfur atom are oriented in opposite directions relative to the four-membered ring GeN 2 S skeleton.The rhodium atom exhibits a distorted planar square geometry.The Ge-Rh bond length [2.3924(4) Å] of 2, which lies within the range of previously reported germylene-Rh(I) complexes [2.3366(9)-2.4499(8) Å] [34][35][36][37][38][39].The Ge-Cl bond length [2.2620( 6) Å] of 2 is somewhat shorter than that of the starting 1 [2.3498( 19) Å] [33].This shortening of the bond length can be attributed to the coordination of the lone-pair electron on the germanium atom to the rhodium atom, leading to a decrease in electron density on the germanium atom that is a factor to the elongation of the Ge-Cl bond in 1 due to the electronic repulsive interaction between both atoms.The average Rh-C distance (2.204 Å) to the carbon atom (C19, C20) positioned trans to the germanium atom is longer than the distance to the cis-oriented carbon atoms (2.126 Å), indicating the strong trans influence of the germylene ligand.
phenyl group on the sulfur atom are oriented in opposite directions relative to the fourmembered ring GeN2S skeleton.The rhodium atom exhibits a distorted planar square geometry.The Ge-Rh bond length [2.3924(4) Å] of 2, which lies within the range of previously reported germylene-Rh(I) complexes [2.3366(9)-2.4499(8) Å] [34][35][36][37][38][39].The Ge-Cl bond length [2.2620( 6) Å] of 2 is somewhat shorter than that of the starting 1 [2.3498(19)Å] [33].This shortening of the bond length can be attributed to the coordination of the lone-pair electron on the germanium atom to the rhodium atom, leading to a decrease in electron density on the germanium atom that is a factor to the elongation of the Ge-Cl bond in 1 due to the electronic repulsive interaction between both atoms.The average Rh-C distance (2.204 Å) to the carbon atom (C19, C20) positioned trans to the germanium atom is longer than the distance to the cis-oriented carbon atoms (2.126 Å), indicating the strong trans influence of the germylene ligand.

General Considerations
Unless otherwise noted, all experiments were carried out under an argon atmosphere using standard Schlenk-line techniques or a glovebox (UNICO Ltd., Ibaraki, Japan). 1 H and 13 C NMR spectra were recorded on Bruker Avance-500 (500 MHz for 1 H) and Bruker Avance-400 (101 MHz for 13 C) spectrometers (Bruker, Kanagawa, Japan) using C 6 D 6 as the solvent at room temperature.IR spectrum was recorded on a TENSOR II (Bruker, Kanagawa, Japan).All melting points were determined on a Mel-Temp capillary tube apparatus and were uncorrected.Elemental analyses were conducted at the Molecular Analysis and Life Science Center of Saitama University.All solvents were dried over 4A molecular sieves or potassium mirrors before use.All materials were obtained from commercial suppliers and used without further purification except 1 that was prepared according to the corresponding literature procedure [33].

Figure 1 .
Figure 1.ORTEP of 2 with thermal ellipsoids at 50% probability.All hydrogen atoms and a molecule of benzene in the unit cell are omitted for clarity.

Figure 1 .
Figure 1.ORTEP of 2 with thermal ellipsoids at 50% probability.All hydrogen atoms and a molecule of benzene in the unit cell are omitted for clarity.

Figure 1 .
Figure 1.ORTEP of 2 with thermal ellipsoids at 50% probability.All hydrogen atoms and a molecule of benzene in the unit cell are omitted for clarity.