Syntheses and Reactions of Derivatives of (Pyrrolylaldiminato)germanium(II) and -Aluminum(III)

(Pyrrolylaldiminato)­germanium­(II) chloride, LGeCl (<b>1</b>), was prepared by reacting LLi (L = 2-(ArNCH)-5-<i>t</i>BuC₄H₂N; Ar = 2,6-<i>i</i>Pr₂C₆H₃) with 1 equiv of GeCl₂·(dioxane). Treatment of LGeCl (<b>1</b>) with KO<i>t</i>Bu or LiN­(H)Ar yielded LGeR (R = O<i>t</i>Bu (<b>2</b>), N­(H)Ar (<b>3</b>)) by halide metathesis. (Pyrrolylaldiminato)­methylaluminum chloride, LAlMe­(Cl) (<b>4</b>), was obtained from the reaction of LLi and MeAlCl₂ or by treating LH with Me₂AlCl in toluene. Treatment of LH with Me₂AlCl or AlCl₃ in Et₂O at −18 °C resulted in the 1:1 adducts LH·AlMe₂Cl (<b>5</b>) and LH·AlCl₃ (<b>5</b>′), respectively. Further reaction of <b>4</b> with 2 equiv of LiNEt₂ led to the insertion of the NEt₂ group into the CN bond together with the elimination of LiCl, to afford L′(NEt₂)­AlMe­(NEt₂)­Li­(THF) (<b>6</b>). Similarly, treatment of <b>4</b> with 2 equiv of LiPPh₂(THF)₂ gave L′(PPh₂)­AlMe­(OC₄H₈-PPh₂)­Li­(THF)₂ (<b>7</b>) accompanied by ring opening of THF. Single-crystal X-ray structure determinations revealed that <b>3</b> and <b>4</b> each contained enantiomeric pairs, while <b>6</b> and <b>7</b> each adopted a single enantiomer

Synthesis and Characterization of Coinage Metal Aluminum Sulfur Species

The synthesis of heterobimetallic cluster with the Al–S–M (M = Cu and Ag) structural unit has been realized for the first time by the reaction of aluminum-dithiol LAl­(SH)₂ (L = HC­[C­(Me)­N­(Ar)]₂, Ar = 2,6-<i>i</i>Pr₂C₆H₃) with (MesCu)₄ and (MesAg)₄ (Mes = 2,4,6-Me₃C₆H₂), respectively. The isolated clusters exhibit core structures of Al₂Cu₄S₄ and Al₄Ag₈S₈, respectively. During the formation of the [LAl­(SAg)₂]₄, a side product of LAlS₆ is formed. However, the reaction of LAl­(SH)₂ with excess of sulfur and (MesAg)₄ resulted in the formation of LAlS₄ as the only product soluble in organic solvents. Both of them represent rare examples of aluminum polysulfides. All compounds were characterized by spectroscopic methods and single crystal X-ray diffraction studies

Syntheses and Reactions of Derivatives of (Pyrrolylaldiminato)germanium(II) and -Aluminum(III)

(Pyrrolylaldiminato)­germanium­(II) chloride, LGeCl (<b>1</b>), was prepared by reacting LLi (L = 2-(ArNCH)-5-<i>t</i>BuC₄H₂N; Ar = 2,6-<i>i</i>Pr₂C₆H₃) with 1 equiv of GeCl₂·(dioxane). Treatment of LGeCl (<b>1</b>) with KO<i>t</i>Bu or LiN­(H)Ar yielded LGeR (R = O<i>t</i>Bu (<b>2</b>), N­(H)Ar (<b>3</b>)) by halide metathesis. (Pyrrolylaldiminato)­methylaluminum chloride, LAlMe­(Cl) (<b>4</b>), was obtained from the reaction of LLi and MeAlCl₂ or by treating LH with Me₂AlCl in toluene. Treatment of LH with Me₂AlCl or AlCl₃ in Et₂O at −18 °C resulted in the 1:1 adducts LH·AlMe₂Cl (<b>5</b>) and LH·AlCl₃ (<b>5</b>′), respectively. Further reaction of <b>4</b> with 2 equiv of LiNEt₂ led to the insertion of the NEt₂ group into the CN bond together with the elimination of LiCl, to afford L′(NEt₂)­AlMe­(NEt₂)­Li­(THF) (<b>6</b>). Similarly, treatment of <b>4</b> with 2 equiv of LiPPh₂(THF)₂ gave L′(PPh₂)­AlMe­(OC₄H₈-PPh₂)­Li­(THF)₂ (<b>7</b>) accompanied by ring opening of THF. Single-crystal X-ray structure determinations revealed that <b>3</b> and <b>4</b> each contained enantiomeric pairs, while <b>6</b> and <b>7</b> each adopted a single enantiomer

Synthesis and Characterization of Heterobimetallic Al–O–Cu Complexes toward Models for Heterogeneous Catalysts on Metal Oxide Surfaces

The β-diketiminato aluminum-monohydroxide and -dihydroxide were reacted with tetrameric (CuMes)₄ (Mes = 2,4,6-Me₃C₆H₂) to prepare Cu­(I) complexes bearing the Al–O–Cu moiety. All complexes are characterized by elemental analysis, nuclear magnetic resonance, and single-crystal X-ray diffraction. The reaction of aluminum–monohydroxide LAlR­(OH) (L = HC­[C­(Me)­N­(Ar)]₂; Ar = 2,6-<i>i</i>Pr₂C₆H₃; R = Me, Et) with (CuMes)₄ afforded the Cu­(I) alumoxane [LAl­(R)­OCu·MesCu]₂ (R = Me, <b>1</b>; Et, <b>2</b>). Using the aluminum-dihydroxide LAl­(OH)₂ as the precursor, the dimeric [LAl­(OH)­OCu·MesCu]₂ (<b>3</b>) was isolated, bearing one reactive OH group on each Al center. When the reaction of LAl­(OH)₂ with (CuMes)₄ was carried out at 70 °C, the dimeric octanuclear Cu­(I) compound [LAl­(OCu·MesCu)₂]₂ (<b>4</b>) was formed, where two residual Mes groups are located at the neighboring position on each of the two (OCu·MesCu)₂ squares. Compound <b>4</b> can be alternatively obtained by reacting <b>3</b> with 1 equiv of (CuMes)₄ to demonstrate the stepwise assembly of the Cu­(I) alumoxanes

Facile Route to Rare Heterobimetallic Aluminum–Copper and Aluminum–Zinc Selenide Clusters

Heterobimetallic aluminum–copper and aluminum–zinc clusters were prepared from the reaction of LAl­(SeH)₂ [<b>1</b>; L = HC­(CMeNAr)₂ and Ar = 2,6-<i>i</i>Pr₂C₆H₃] with (MesCu)₄ and ZnEt₂, respectively. The resulting clusters with the core structures of Al₂Se₄Cu₄ and Al₂Se₄Zn₃ exhibit unique metal–organic frameworks. This is a novel pathway for the synthesis of aluminum–copper and aluminum–zinc selenides. The products have been characterized by spectroscopic methods and single-crystal X-ray structural characterization

β‑Diketiminate Germylene-Supported Pentafluorophenylcopper(I) and -silver(I) Complexes [LGe(Me)(CuC₆F₅)_<i>n</i>]₂ (<i>n</i> = 1, 2), LGe[C(SiMe₃)N₂]AgC₆F₅, and {LGe[C(SiMe₃)N₂](AgC₆F₅)₂}₂ (L = HC[C(Me)N-2,6‑<i>i</i>Pr₂C₆H₃]₂): Synthesis and Structural Characterization

Reactions of LGeMe (L = HC­[C­(Me)­N-2,6-<i>i</i>Pr₂C₆H₃]₂) with 0.25 or 0.5 equiv of (CuC₆F₅)₄ gave the products [LGe­(Me)­CuC₆F₅]₂ (<b>1</b>) and [LGe­(Me)­(CuC₆F₅)₂]₂ (<b>2</b>), respectively. In situ formed <b>1</b> reacted with 0.5 equiv of (CuC₆F₅)₄ to give <b>2</b> on the basis of NMR (¹H and ¹⁹F) spectral measurements. Conversely, <b>2</b> was converted into <b>1</b> by treatment with 2 equiv of LGeMe. Reactions of LGeC­(SiMe₃)­N₂ with 1 or 2 equiv of AgC₆F₅·MeCN produced the corresponding compounds LGe­[C­(SiMe₃)­N₂]­AgC₆F₅ (<b>3</b>) and {LGe­[C­(SiMe₃)­N₂]­(AgC₆F₅)₂}₂ (<b>4</b>). Similarly, <b>3</b> was converted into <b>4</b> by treatment with 1 equiv of AgC₆F₅·MeCN and <b>4</b> converted into <b>3</b> by reaction with 2 equiv of LGeC­(SiMe₃)­N₂. X-ray crystallographic studies showed that <b>1</b> contains a rhombically bridged (CuC₆F₅)₂, while <b>2</b> has a chain-structurally aggregated (CuC₆F₅)₄, both supported by LGeMe. Correspondingly, <b>3</b> showed a terminally bound AgC₆F₅ and <b>4</b> a chain-structurally aggregated (AgC₆F₅)₄, both supported by LGeC­(SiMe₃)­N₂. Photophysical studies proved that the Ge–Cu metal–metalloid donor–acceptor bonding persists in solutions of <b>1</b> and <b>2</b> and Ge–Ag donor–acceptor bonding in solutions of <b>3</b> and <b>4</b> as a result of the clear migration of their emission bands compared to those of the corresponding starting materials. Low-temperature (−50 °C) ¹⁹F NMR spectral measurements detected dissociation of <b>1</b>, <b>2</b>, and <b>4</b> by the aggregation part of the CuC₆F₅ or AgC₆F₅ entities in solution. These results provide good support for pentafluorophenylcopper­(I) or -silver­(I) species having β-diketiminate germylene as a donor because of its remarkably electronic and steric character

β‑Diketiminate Germylene-Supported Pentafluorophenylcopper(I) and -silver(I) Complexes [LGe(Me)(CuC₆F₅)_<i>n</i>]₂ (<i>n</i> = 1, 2), LGe[C(SiMe₃)N₂]AgC₆F₅, and {LGe[C(SiMe₃)N₂](AgC₆F₅)₂}₂ (L = HC[C(Me)N-2,6‑<i>i</i>Pr₂C₆H₃]₂): Synthesis and Structural Characterization

Reactions of LGeMe (L = HC­[C­(Me)­N-2,6-<i>i</i>Pr₂C₆H₃]₂) with 0.25 or 0.5 equiv of (CuC₆F₅)₄ gave the products [LGe­(Me)­CuC₆F₅]₂ (<b>1</b>) and [LGe­(Me)­(CuC₆F₅)₂]₂ (<b>2</b>), respectively. In situ formed <b>1</b> reacted with 0.5 equiv of (CuC₆F₅)₄ to give <b>2</b> on the basis of NMR (¹H and ¹⁹F) spectral measurements. Conversely, <b>2</b> was converted into <b>1</b> by treatment with 2 equiv of LGeMe. Reactions of LGeC­(SiMe₃)­N₂ with 1 or 2 equiv of AgC₆F₅·MeCN produced the corresponding compounds LGe­[C­(SiMe₃)­N₂]­AgC₆F₅ (<b>3</b>) and {LGe­[C­(SiMe₃)­N₂]­(AgC₆F₅)₂}₂ (<b>4</b>). Similarly, <b>3</b> was converted into <b>4</b> by treatment with 1 equiv of AgC₆F₅·MeCN and <b>4</b> converted into <b>3</b> by reaction with 2 equiv of LGeC­(SiMe₃)­N₂. X-ray crystallographic studies showed that <b>1</b> contains a rhombically bridged (CuC₆F₅)₂, while <b>2</b> has a chain-structurally aggregated (CuC₆F₅)₄, both supported by LGeMe. Correspondingly, <b>3</b> showed a terminally bound AgC₆F₅ and <b>4</b> a chain-structurally aggregated (AgC₆F₅)₄, both supported by LGeC­(SiMe₃)­N₂. Photophysical studies proved that the Ge–Cu metal–metalloid donor–acceptor bonding persists in solutions of <b>1</b> and <b>2</b> and Ge–Ag donor–acceptor bonding in solutions of <b>3</b> and <b>4</b> as a result of the clear migration of their emission bands compared to those of the corresponding starting materials. Low-temperature (−50 °C) ¹⁹F NMR spectral measurements detected dissociation of <b>1</b>, <b>2</b>, and <b>4</b> by the aggregation part of the CuC₆F₅ or AgC₆F₅ entities in solution. These results provide good support for pentafluorophenylcopper­(I) or -silver­(I) species having β-diketiminate germylene as a donor because of its remarkably electronic and steric character

Reactivity Studies of (Phenylethynyl)germylene LGeCCPh (L = HC[C(Me)N-2,6‑<i>i</i>Pr₂C₆H₃]₂) toward Pentafluorophenylcopper(I), -silver(I), and -gold(I) Complexes

Reactions of (phenylethynyl)­germylene LGeCCPh (L = HC­[C­(Me)­N-2,6-<i>i</i>Pr₂C₆H₃]₂) with 0.25 equiv of (CuC₆F₅)₄, 1 equiv of AgC₆F₅·MeCN, and 1 equiv of AuC₆F₅·SC₄H₈, respectively, yielded LGe­(CCPh)­CuC₆F₅ (<b>1</b>), [(LGeCCPh)₂Ag]⁺[Ag­(C₆F₅)₂]⁻ (<b>2</b>), and LGe­(CCPh)­AuC₆F₅ (<b>3</b>). Complexes <b>1</b>–<b>3</b> were characterized by IR and NMR spectroscopy and X-ray crystallography. Compound <b>1</b> shows a bonding pattern of the CuC₆F₅ entity by both the phenylethynyl CC linkage and the L ligand backbone of the γ-C atom, while <b>3</b> exhibits a bonding mode of the AuC₆F₅ entity at the germylene center. Compound <b>2</b> is an ionic derivative featuring the Ge–Ag donor–acceptor bond formed under redistribution of the AgC₆F₅ entity. Further reactions of <b>1</b> with (CuC₆F₅)₄, AgC₆F₅·MeCN, and AuC₆F₅·SC₄H₈ afforded the complexes LGe­(CCPh)­(CuC₆F₅)­(MC₆F₅) (M = Cu (<b>4</b>), Ag (<b>5</b>), Au (<b>6</b>)). Compounds <b>4</b>–<b>6</b> were characterized by IR and NMR spectroscopy, and <b>5</b> and <b>6</b> were further investigated by X-ray crystallography. Compounds <b>4</b>–<b>6</b> all show an additional bonding of the respective MC₆F₅ moiety at the germylene center of <b>1</b>. These studies reveal a multiple donor reactivity of LGeCCPh. The slightly different Lewis acidic properties of the congeneric pentafluorophenylcopper­(I), -silver­(I), and -gold­(I) complexes as acceptors are thus disclosed

Reactivity Studies of (Phenylethynyl)germylene LGeCCPh (L = HC[C(Me)N-2,6‑<i>i</i>Pr₂C₆H₃]₂) toward Pentafluorophenylcopper(I), -silver(I), and -gold(I) Complexes

Reactions of (phenylethynyl)­germylene LGeCCPh (L = HC­[C­(Me)­N-2,6-<i>i</i>Pr₂C₆H₃]₂) with 0.25 equiv of (CuC₆F₅)₄, 1 equiv of AgC₆F₅·MeCN, and 1 equiv of AuC₆F₅·SC₄H₈, respectively, yielded LGe­(CCPh)­CuC₆F₅ (<b>1</b>), [(LGeCCPh)₂Ag]⁺[Ag­(C₆F₅)₂]⁻ (<b>2</b>), and LGe­(CCPh)­AuC₆F₅ (<b>3</b>). Complexes <b>1</b>–<b>3</b> were characterized by IR and NMR spectroscopy and X-ray crystallography. Compound <b>1</b> shows a bonding pattern of the CuC₆F₅ entity by both the phenylethynyl CC linkage and the L ligand backbone of the γ-C atom, while <b>3</b> exhibits a bonding mode of the AuC₆F₅ entity at the germylene center. Compound <b>2</b> is an ionic derivative featuring the Ge–Ag donor–acceptor bond formed under redistribution of the AgC₆F₅ entity. Further reactions of <b>1</b> with (CuC₆F₅)₄, AgC₆F₅·MeCN, and AuC₆F₅·SC₄H₈ afforded the complexes LGe­(CCPh)­(CuC₆F₅)­(MC₆F₅) (M = Cu (<b>4</b>), Ag (<b>5</b>), Au (<b>6</b>)). Compounds <b>4</b>–<b>6</b> were characterized by IR and NMR spectroscopy, and <b>5</b> and <b>6</b> were further investigated by X-ray crystallography. Compounds <b>4</b>–<b>6</b> all show an additional bonding of the respective MC₆F₅ moiety at the germylene center of <b>1</b>. These studies reveal a multiple donor reactivity of LGeCCPh. The slightly different Lewis acidic properties of the congeneric pentafluorophenylcopper­(I), -silver­(I), and -gold­(I) complexes as acceptors are thus disclosed

N‑Geminal P/Al Lewis Pair–Alkyne Dipolar Cycloaddition to the Zwitterionic C₂PNAl-Heterocyclopentene

The N-geminal P/Al Lewis pair [Ph₂PN­(2,6-<i>i</i>Pr₂C₆H₃)­AlEt₂]₂ (<b>1</b>) has been prepared and studied for reaction with a series of alkynes. The reaction of <b>1</b> with RCCR yielded zwitterionic C₂PNAl-heterocyclopentene [Ph₂PN­(2,6-<i>i</i>Pr₂C₆H₃)­AlEt₂]­(CRCR) (R = Me (<b>2</b>), Ph (<b>3</b>)); with PhCCEt produced two isomers, [Ph₂PN­(2,6-<i>i</i>Pr₂C₆H₃)­AlEt₂]­(CPhCEt) (<b>4a</b>) and [Ph₂PN­(2,6-<i>i</i>Pr₂C₆H₃)­AlEt₂]­(CEt­CPh) (<b>4b</b>); and with other alkynes generated [Ph₂PN­(2,6-<i>i</i>Pr₂C₆H₃)­AlEt₂]­(CR¹CR²) (R¹, R² = CO₂Et, Ph (<b>5</b>); SiMe₃, Ph (<b>6</b>); PPh₂, Ph (<b>7</b>); SiMe₃,H (<b>8</b>); H, EtO (<b>9</b>)). Natural bond orbital analysis of the charge separation of the CC bond of alkynes was carried out, and then, the electronic matching interaction mode between the combined Lewis acid (AlEt₂) and base (PPh₂) groups of <b>1</b> and the CC bond of such alkynes was discussed. Reactions of <b>1</b> with alkene, nitrile, and carbodiimide molecules were also carried out, and cycloaddition compounds <b>10</b>–<b>12</b> were produced