syn−anti Conversion in Octahedral Bis(β-diketonato)diorganotin(IV) Derivatives Containing Fluorinated 4-Acyl-5-pyrazolonato Donors

Diorganotin(IV) complexes of dideprotonated pyridoxine (PN, vitamin B6). The crystal structures of [SnEt2(PN–2H)]·CH3OH, [SnEt2(PN–2H)(DMSO)] and [SnBu2(PN–2H)]

“…Although 119 Sn chemical shifts are influenced by several factors [21], the coordination mode of the tin atom is one of the most important [22]; the values obtained for 2 and 4 are in the range reported [23] for pentacoordinated tin, which is compatible especially in the case of the ethyl derivative, with there being significant coordination of DMSO (as is also suggested by the formation of 3). Complex 1 presents two signals located at )204.7 and )216.7, suggesting the presence of two slightly different types of molecule in solution.…”

Diorganotin(IV) complexes of dideprotonated pyridoxine (PN, vitamin B6). The crystal structures of [SnEt2(PN–2H)]·CH3OH, [SnEt2(PN–2H)(DMSO)] and [SnBu2(PN–2H)]

“…Although 119 Sn chemical shifts are influenced by several factors [21], the coordination mode of the tin atom is one of the most important [22]; the values obtained for 2 and 4 are in the range reported [23] for pentacoordinated tin, which is compatible especially in the case of the ethyl derivative, with there being significant coordination of DMSO (as is also suggested by the formation of 3). Complex 1 presents two signals located at )204.7 and )216.7, suggesting the presence of two slightly different types of molecule in solution.…”

Synthesis, Molecular Structure (X-ray and DFT), and Solution Behavior of Titanium 4-Acyl-5-pyrazolonates. Correlations with Related Antitumor β-Diketonato Derivatives

“…The marked differences in these three sets of Ti−O bonds suggest that the metal coordination sphere is governed by trans influence features. We have already observed that in other 4-acyl-5-pyrazolonato metal complexes the O(pyrazolonato) tends to establish shorter metal−oxygen bonds than O(acyl). − The rationale for this is that the acyl carbonyl provides a coordinative lone pair with weaker donation than the covalent O(pyrazolonato) anionic moiety. For benzoylacetonato, the pattern is less clear (Figure ) because the O(near-Ph) and O(near-Met) donors can form either a shorter or a longer metal−oxygen length .…”

“…A demonstration of this feature is given by the square-planar complex bis(triphenylphosphine)-(1-phenyl-3-methyl-4-(2-thienoyl)pyrazol-5-one)-rhodium(I), where O(acyl) and O(pyrazolonato) are both trans to the PPh 3 groups; as a result, the Rh−O(pyrazolonato) and Rh−O(acyl) bond lengths are equal . Nevertheless, the tendency for the O(acyl) group to establish a metal−O(acyl) bond length longer than metal−O(pyrazolonato) in this study is consistent with previous results, , and so it appears logical for O(acyl) to be displayed trans to the short Ti−O(ethoxy) groups in compound 1 . The same applies for compound 1 ‘, where those groups trans to O(acyl) are again the short Ti−O(oxo) and Ti−O(ethoxy) groups.…”

Silver Coordination Chemistry of a New Versatile “Janus”-type N2,O2-Bichelating Donor, Formation of an Unprecedented Supramolecular Network of Binuclear Silver Building Blocks Containing a Five-Coordinate β-Diketonate, and Isolation of Unexpected Silver−Tin−Silver Heterotrimetallic Complexes from Silver Metathesis Reactions

“…Moreover, in the spectrum of 13 two new bands at 265 and 228 cm -1 have been tentatively assigned to Sn-Ph; in the spectrum of 14 a strong band at 587 cm -1 has been assigned to Sn-Bu n , following previous reports. [25][26][27][28] The 119 Sn NMR spectra of 13 and 14 exhibit resonances at -495 and -441 ppm, respectively, both typical of six-coordinated tin. In the low temperature 31 P NMR of 13 and 14, a resonance with 1 J P-Ag of ca.…”

Diorganotin(IV) complexes of dideprotonated pyridoxine (PN, vitamin B6). The crystal structures of [SnEt2(PN–2H)]·CH3OH, [SnEt2(PN–2H)(DMSO)] and [SnBu2(PN–2H)]

“…Although 119 Sn chemical shifts are influenced by several factors [21], the coordination mode of the tin atom is one of the most important [22]; the values obtained for 2 and 4 are in the range reported [23] for pentacoordinated tin, which is compatible especially in the case of the ethyl derivative, with there being significant coordination of DMSO (as is also suggested by the formation of 3). Complex 1 presents two signals located at )204.7 and )216.7, suggesting the presence of two slightly different types of molecule in solution.…”

Synthesis, Molecular Structure (X-ray and DFT), and Solution Behavior of Titanium 4-Acyl-5-pyrazolonates. Correlations with Related Antitumor β-Diketonato Derivatives

“…The marked differences in these three sets of Ti−O bonds suggest that the metal coordination sphere is governed by trans influence features. We have already observed that in other 4-acyl-5-pyrazolonato metal complexes the O(pyrazolonato) tends to establish shorter metal−oxygen bonds than O(acyl). − The rationale for this is that the acyl carbonyl provides a coordinative lone pair with weaker donation than the covalent O(pyrazolonato) anionic moiety. For benzoylacetonato, the pattern is less clear (Figure ) because the O(near-Ph) and O(near-Met) donors can form either a shorter or a longer metal−oxygen length .…”

“…A demonstration of this feature is given by the square-planar complex bis(triphenylphosphine)-(1-phenyl-3-methyl-4-(2-thienoyl)pyrazol-5-one)-rhodium(I), where O(acyl) and O(pyrazolonato) are both trans to the PPh 3 groups; as a result, the Rh−O(pyrazolonato) and Rh−O(acyl) bond lengths are equal . Nevertheless, the tendency for the O(acyl) group to establish a metal−O(acyl) bond length longer than metal−O(pyrazolonato) in this study is consistent with previous results, , and so it appears logical for O(acyl) to be displayed trans to the short Ti−O(ethoxy) groups in compound 1 . The same applies for compound 1 ‘, where those groups trans to O(acyl) are again the short Ti−O(oxo) and Ti−O(ethoxy) groups.…”

Silver Coordination Chemistry of a New Versatile “Janus”-type N2,O2-Bichelating Donor, Formation of an Unprecedented Supramolecular Network of Binuclear Silver Building Blocks Containing a Five-Coordinate β-Diketonate, and Isolation of Unexpected Silver−Tin−Silver Heterotrimetallic Complexes from Silver Metathesis Reactions

“…Moreover, in the spectrum of 13 two new bands at 265 and 228 cm -1 have been tentatively assigned to Sn-Ph; in the spectrum of 14 a strong band at 587 cm -1 has been assigned to Sn-Bu n , following previous reports. [25][26][27][28] The 119 Sn NMR spectra of 13 and 14 exhibit resonances at -495 and -441 ppm, respectively, both typical of six-coordinated tin. In the low temperature 31 P NMR of 13 and 14, a resonance with 1 J P-Ag of ca.…”

Diorganotin(IV) complexes of dideprotonated pyridoxine (PN, vitamin B6). The crystal structures of [SnEt2(PN–2H)]·CH3OH, [SnEt2(PN–2H)(DMSO)] and [SnBu2(PN–2H)]

“…Although 119 Sn chemical shifts are influenced by several factors [21], the coordination mode of the tin atom is one of the most important [22]; the values obtained for 2 and 4 are in the range reported [23] for pentacoordinated tin, which is compatible especially in the case of the ethyl derivative, with there being significant coordination of DMSO (as is also suggested by the formation of 3). Complex 1 presents two signals located at )204.7 and )216.7, suggesting the presence of two slightly different types of molecule in solution.…”

Synthesis, Molecular Structure (X-ray and DFT), and Solution Behavior of Titanium 4-Acyl-5-pyrazolonates. Correlations with Related Antitumor β-Diketonato Derivatives

“…The marked differences in these three sets of Ti−O bonds suggest that the metal coordination sphere is governed by trans influence features. We have already observed that in other 4-acyl-5-pyrazolonato metal complexes the O(pyrazolonato) tends to establish shorter metal−oxygen bonds than O(acyl). − The rationale for this is that the acyl carbonyl provides a coordinative lone pair with weaker donation than the covalent O(pyrazolonato) anionic moiety. For benzoylacetonato, the pattern is less clear (Figure ) because the O(near-Ph) and O(near-Met) donors can form either a shorter or a longer metal−oxygen length .…”

“…A demonstration of this feature is given by the square-planar complex bis(triphenylphosphine)-(1-phenyl-3-methyl-4-(2-thienoyl)pyrazol-5-one)-rhodium(I), where O(acyl) and O(pyrazolonato) are both trans to the PPh 3 groups; as a result, the Rh−O(pyrazolonato) and Rh−O(acyl) bond lengths are equal . Nevertheless, the tendency for the O(acyl) group to establish a metal−O(acyl) bond length longer than metal−O(pyrazolonato) in this study is consistent with previous results, , and so it appears logical for O(acyl) to be displayed trans to the short Ti−O(ethoxy) groups in compound 1 . The same applies for compound 1 ‘, where those groups trans to O(acyl) are again the short Ti−O(oxo) and Ti−O(ethoxy) groups.…”

Silver Coordination Chemistry of a New Versatile “Janus”-type N2,O2-Bichelating Donor, Formation of an Unprecedented Supramolecular Network of Binuclear Silver Building Blocks Containing a Five-Coordinate β-Diketonate, and Isolation of Unexpected Silver−Tin−Silver Heterotrimetallic Complexes from Silver Metathesis Reactions

“…Moreover, in the spectrum of 13 two new bands at 265 and 228 cm -1 have been tentatively assigned to Sn-Ph; in the spectrum of 14 a strong band at 587 cm -1 has been assigned to Sn-Bu n , following previous reports. [25][26][27][28] The 119 Sn NMR spectra of 13 and 14 exhibit resonances at -495 and -441 ppm, respectively, both typical of six-coordinated tin. In the low temperature 31 P NMR of 13 and 14, a resonance with 1 J P-Ag of ca.…”