New Structural Forms of Organostannoxane Macrocycle Networks

The reaction of pyrazole-3,5-dicarboxylic acid with dibenzyltin dichloride in the presence of potassium hydroxide affords a novel 2D network containing rectangular box type hexatin units interconnected by two Bz2SnCl bridging groups. Hydrolysis of the latter affords a polymeric tape containing alternate hexatin macrocycle and tetratin ladder motifs

Di- and Trinuclear Complexes Derived from Hexakis(2-pyridyloxy)cyclotriphosphazene. Unusual P−O Bond Cleavage in the Formation of [{(L^‘CuCl)₂(Co(NO₃)}Cl] (L‘ = N₃P₃(OC₅H₄N)₅(O))

Hexakis(2-pyridyloxy)cyclotriphosphazene (L) is an efficient multisite coordination ligand which binds with transition metal ions to produce dinuclear (homo- and heterometallic) complexes [L(CuCl)(CoCl3)], [L(CuCl)(ZnCl3)], [L(CoCl)(ZnCl3)], and [L(ZnCl2)2]. In these dinuclear derivatives the cyclophosphazene ligand utilizes from five to six nitrogen coordination sites out of the maximum of nine available sites. Further, the spacer oxygen that separates the pyridyl moiety from the cyclophosphazene ring ensures minimum steric strain to the cyclophosphazene ring upon coordination. This is reflected in the near planarity of the cyclophosphazene ring in all the dinuclear derivatives. In the dinuclear heterobimetallic derivatives one of the metal ions [Cu(II) or Co(II)] is hexacoordinate and is bound by the cyclophosphazene in a η5-gem-N5 mode. The other metal ion in these heterobimetallic derivatives [Co(II) or Zn(II)] is tetracoordinate and is bound in an η1-N1 fashion. In the homobimetallic derivative, [L(ZnCl2)2], one of the zinc ions is five-coordinate (η3-nongem-N3), while the other zinc ion is tetracoordinate(η2-gem-N2). The reaction of L with CuCl2 followed by Co(NO3)2·6H2O yields a trinuclear heterobimetallic complex [{(L‘CuCl)2Co(NO3)}Cl] [L‘ = N3P3(OC5H4N)5(O)]. In the formation of this compound an unusual P−O bond cleavage involving one of the phosphorus−pyridyloxy bonds is observed. The molecular structure of [{(L‘CuCl)2Co(NO3)}Cl] [L‘ = N3P3(OC5H4N)5(O)] reveals that each of the two the P−O-cleaved L‘ ligands is involved in binding to Cu(II) to generate the motif L‘CuCl. Two such units are bridged by a Co(II) ion. The coordination environment around the bridging Co(II) ion contains four oxygen (two P−O units, one chelating nitrate) and two nitrogen atoms (pyridyloxy nitrogens)

Di- and Trinuclear Complexes Derived from Hexakis(2-pyridyloxy)cyclotriphosphazene. Unusual P−O Bond Cleavage in the Formation of [{(L^‘CuCl)₂(Co(NO₃)}Cl] (L‘ = N₃P₃(OC₅H₄N)₅(O))

Hexakis(2-pyridyloxy)cyclotriphosphazene (L) is an efficient multisite coordination ligand which binds with transition metal ions to produce dinuclear (homo- and heterometallic) complexes [L(CuCl)(CoCl3)], [L(CuCl)(ZnCl3)], [L(CoCl)(ZnCl3)], and [L(ZnCl2)2]. In these dinuclear derivatives the cyclophosphazene ligand utilizes from five to six nitrogen coordination sites out of the maximum of nine available sites. Further, the spacer oxygen that separates the pyridyl moiety from the cyclophosphazene ring ensures minimum steric strain to the cyclophosphazene ring upon coordination. This is reflected in the near planarity of the cyclophosphazene ring in all the dinuclear derivatives. In the dinuclear heterobimetallic derivatives one of the metal ions [Cu(II) or Co(II)] is hexacoordinate and is bound by the cyclophosphazene in a η5-gem-N5 mode. The other metal ion in these heterobimetallic derivatives [Co(II) or Zn(II)] is tetracoordinate and is bound in an η1-N1 fashion. In the homobimetallic derivative, [L(ZnCl2)2], one of the zinc ions is five-coordinate (η3-nongem-N3), while the other zinc ion is tetracoordinate(η2-gem-N2). The reaction of L with CuCl2 followed by Co(NO3)2·6H2O yields a trinuclear heterobimetallic complex [{(L‘CuCl)2Co(NO3)}Cl] [L‘ = N3P3(OC5H4N)5(O)]. In the formation of this compound an unusual P−O bond cleavage involving one of the phosphorus−pyridyloxy bonds is observed. The molecular structure of [{(L‘CuCl)2Co(NO3)}Cl] [L‘ = N3P3(OC5H4N)5(O)] reveals that each of the two the P−O-cleaved L‘ ligands is involved in binding to Cu(II) to generate the motif L‘CuCl. Two such units are bridged by a Co(II) ion. The coordination environment around the bridging Co(II) ion contains four oxygen (two P−O units, one chelating nitrate) and two nitrogen atoms (pyridyloxy nitrogens)

New Structural Forms of Organostannoxane Macrocycle Networks

The reaction of pyrazole-3,5-dicarboxylic acid with dibenzyltin dichloride in the presence of potassium hydroxide affords a novel 2D network containing rectangular box type hexatin units interconnected by two Bz2SnCl bridging groups. Hydrolysis of the latter affords a polymeric tape containing alternate hexatin macrocycle and tetratin ladder motifs

Reactivity of Stable Heteroleptic Silylene PhC(N<i>t</i>Bu)₂SiNPh₂ toward Diazobenzene and <i>N</i>‑Benzylidineaniline

The reaction of heteroleptic silylene LSiNPh₂ [L = PhC­(N<i>t</i>Bu)₂] with diazobenzene afforded product <b>6</b>. This involves one <i>o</i>-C–H bond activation at one of the phenyl groups of diazobenzene and migration of this hydrogen atom from the phenyl ring to one of the nitrogen atoms, which leads to the formation of the new C–Si and N–Si bonds. The reaction of benzylidineaniline with LSiNPh₂ results in the oxidative addition of the three-membered silaaziridine derivative <b>7</b>. Compounds <b>6</b> and <b>7</b> were fully characterized by elemental analysis, multinuclear NMR spectroscopy, and EI-MS spectrometry. The molecular structures of compounds <b>6</b> and <b>7</b> were established unequivocally by single-crystal X-ray structural analysis

Influence of O−H···OP Hydrogen Bonding on the Supramolecular Architectures of Phosphorus-Based Hydrazones: Alternate Right- and Left-Handed Fused Helical Chains Based on O−H···OP Hydrogen Bonds in the Crystal Structure of C₆H₅P(O)[N(CH₃)NCHC₆H₄-<i>p</i>-OH]₂

The acyclic phosphorus dihydrazone C6H5P(O)[N(CH3)NCHC6H4-p-OH]2 (1) forms an alternate right- and left-handed fused helical chain supramolecular structure in the solid state. The supramolecular architecture of 1 is formed as a result of intermolecular O−H···OP interactions. Variation in the position of the hydroxy group in C6H5P(O)[N(CH3)NCHC6H4-m-OH]2 (2) leads to the formation of a ladder structure, also mediated by O−H···OP interactions. In contrast to 1 and 2, C6H5[N(CH3)NCHC6H4-o-OH]2 (3), which contains an o-hydroxy group on the phenyl substituents, only shows C−H···O interactions. The absence of O−H···OP interactions in the latter is attributed to the involvement of the O−H unit in intramolecular O−H···N hydrogen bonding

Reactivity Studies of Heteroleptic Silylenes with N₂O

Reaction of heteroleptic silylenes LSiX (L = PhC­(N<i>t</i>Bu)₂; X = PPh₂ (<b>1</b>), NPh₂ (<b>2</b>), NMe₂ (<b>3</b>), O<i>t</i>Bu (<b>4</b>)) with N₂O resulted in the oxidized dimeric product [LSi­(X)­(μ-O)]₂ (X = PPh₂ (<b>5</b>), NPh₂ (<b>6</b>), NMe₂ (<b>7</b>), O<i>t</i>Bu (<b>8</b>)), which contains a four-membered Si₂O₂ ring. Compounds <b>5</b>–<b>8</b> were characterized by spectroscopic and spectrometric techniques. The molecular structures of <b>5</b>–<b>8</b> were established by single-crystal X-ray structure analysis

Reactivity Studies of Heteroleptic Silylenes with N₂O

Reaction of heteroleptic silylenes LSiX (L = PhC­(N<i>t</i>Bu)₂; X = PPh₂ (<b>1</b>), NPh₂ (<b>2</b>), NMe₂ (<b>3</b>), O<i>t</i>Bu (<b>4</b>)) with N₂O resulted in the oxidized dimeric product [LSi­(X)­(μ-O)]₂ (X = PPh₂ (<b>5</b>), NPh₂ (<b>6</b>), NMe₂ (<b>7</b>), O<i>t</i>Bu (<b>8</b>)), which contains a four-membered Si₂O₂ ring. Compounds <b>5</b>–<b>8</b> were characterized by spectroscopic and spectrometric techniques. The molecular structures of <b>5</b>–<b>8</b> were established by single-crystal X-ray structure analysis

Influence of O−H···OP Hydrogen Bonding on the Supramolecular Architectures of Phosphorus-Based Hydrazones: Alternate Right- and Left-Handed Fused Helical Chains Based on O−H···OP Hydrogen Bonds in the Crystal Structure of C₆H₅P(O)[N(CH₃)NCHC₆H₄-<i>p</i>-OH]₂

The acyclic phosphorus dihydrazone C6H5P(O)[N(CH3)NCHC6H4-p-OH]2 (1) forms an alternate right- and left-handed fused helical chain supramolecular structure in the solid state. The supramolecular architecture of 1 is formed as a result of intermolecular O−H···OP interactions. Variation in the position of the hydroxy group in C6H5P(O)[N(CH3)NCHC6H4-m-OH]2 (2) leads to the formation of a ladder structure, also mediated by O−H···OP interactions. In contrast to 1 and 2, C6H5[N(CH3)NCHC6H4-o-OH]2 (3), which contains an o-hydroxy group on the phenyl substituents, only shows C−H···O interactions. The absence of O−H···OP interactions in the latter is attributed to the involvement of the O−H unit in intramolecular O−H···N hydrogen bonding

Cyclophosphazene-Supported Tetranuclear Copper Assembly Containing 15 Contiguous Inorganic Rings

The cyclophosphazene hydrazide gem-N3P3Ph2[N(Me)NH2]4 was reacted with o-hydroxybenzaldehyde to afford the multisite coordination ligand gem-N3P3Ph2[N(Me)NCHC6H4-2-OH]4 (LH4). The latter reacted with copper(II) salts to afford a novel tetranuclear copper assembly {N3P3Ph2[N(Me)NCHC6H4-2-O]4Cu2}2, which contains, remarkably, 15 contiguous inorganic rings