Structural and reactivity investigations using organo-copper(i) and zinc(ii) complexes with hydrogen and carbon dioxide

Bradley E. Cowie; Andreas Phanopoulos; Milo S.P. Shaffer; Charlotte K. Williams

doi:10.1039/d5sc05666g

Structural and reactivity investigations using organo-copper(i) and zinc(ii) complexes with hydrogen and carbon dioxide

Bradley E. Cowie, Andreas Phanopoulos, Milo S.P. Shaffer, Charlotte K. Williams

Research output: Contribution to journal › Article › peer-review

Abstract

Heterogeneous copper zinc catalysts are widely used in syn-gas or carbon dioxide hydrogenation to methanol, but the structures and reactivity at the catalytic active sites are still not fully understood. Well-defined metal complexes and clusters may help reveal the structures of key intermediates, including for catalytic reactions involving gaseous species. Here, a tri-copper(i) complex, [Cu₃{µ:κ³(PPC)-dppm′}₂{µ:κ²(PP)-dppm′}] 1 (dppm′ = [(Ph₂P)₂CH]⁻) is used as the starting point to investigate reactivity with hydrogen and carbon dioxide in solution and at low temperatures (20–60 °C) and gas pressures (1 bar or lower). Complex 1 reacts with hydrogen to afford a copper-hydride cluster, [Cu₅(µ-H)(µ₃-H)₂(µ:κ³(PPC)-dppm′)₂(µ:κ²(PP)-dppm)₂] 2, which contains five Cu^I centres and three hydrido ligands. The reaction of 2 with carbon dioxide provides a tri-copper(i)-bis(formate)(hydrido) complex, [Cu₃(µ₃-H)(κ¹(O)-O₂CH)(µ:κ²(OO)-O₂CH)(µ:κ²(PP)-dppm)₃] 3, in which two molecules of carbon dioxide react with the hydrides to produce formate ligands. Treating 1 with an organozinc(ii) complex, [Zn(C₆F₅)₂], affords a hetero-tetrametallic Cu^I₂Zn^II₂ complex, [Cu₂(µ:κ³(PPC)-dppm′)₂{Zn(C₆F₅)₂}₂] 4. Complex 4 features two cationic Cu(i) and two anionic Zn(ii) centres, adopting an unusual copper zincate speciation, and reacts with carbon dioxide to form a bis(carboxylate)-Cu^I₂Zn^II₂ complex, [Cu₂(µ:κ⁴(PPOO)-dppm″)₂{Zn(C₆F₅)₂}₂] 5; carbon dioxide inserts into the Zn–C bond and forms a new C–C bond with the methine carbon of the dppm′ ligand. Overall, the structures and reactivity indicate that Cu^I sites readily form hydrides, on exposure to hydrogen; these cuprous hydrides react with CO₂ to produce formate, and cuprous zincates react with CO₂ to afford carboxylates.

Original language	English
Pages (from-to)	564-578
Number of pages	15
Journal	Chemical Science
Volume	17
Issue number	1
Early online date	18 Nov 2025
DOIs	https://doi.org/10.1039/d5sc05666g
Publication status	Published - 7 Jan 2026

Data Availability Statement

CCDC 2269234–2269239 (1–6) contain the supplementary crystallographic data for this paper.115a–f

The data supporting this article have been included as part of the supplementary information (SI). Supplementary information: full experimental details and procedures, tables of structural and spectroscopic metrics for comparison with similar compounds reported in the literature, characterisation data (1H, 2H, 13C{1H}, 31P{1H} and 19F{1H} NMR, FT-IR, and crystallographic details), and computational methods. See DOI: https://doi.org/10.1039/d5sc05666g.

ASJC Scopus subject areas

General Chemistry

Access to Document

10.1039/d5sc05666gLicence: CC BY-NC

Cite this

@article{343aa0a190a14647be0423d239f89e2f,

title = "Structural and reactivity investigations using organo-copper(i) and zinc(ii) complexes with hydrogen and carbon dioxide",

abstract = "Heterogeneous copper zinc catalysts are widely used in syn-gas or carbon dioxide hydrogenation to methanol, but the structures and reactivity at the catalytic active sites are still not fully understood. Well-defined metal complexes and clusters may help reveal the structures of key intermediates, including for catalytic reactions involving gaseous species. Here, a tri-copper(i) complex, [Cu3\{µ:κ3(PPC)-dppm′\}2\{µ:κ2(PP)-dppm′\}] 1 (dppm′ = [(Ph2P)2CH]−) is used as the starting point to investigate reactivity with hydrogen and carbon dioxide in solution and at low temperatures (20–60 °C) and gas pressures (1 bar or lower). Complex 1 reacts with hydrogen to afford a copper-hydride cluster, [Cu5(µ-H)(µ3-H)2(µ:κ3(PPC)-dppm′)2(µ:κ2(PP)-dppm)2] 2, which contains five CuI centres and three hydrido ligands. The reaction of 2 with carbon dioxide provides a tri-copper(i)-bis(formate)(hydrido) complex, [Cu3(µ3-H)(κ1(O)-O2CH)(µ:κ2(OO)-O2CH)(µ:κ2(PP)-dppm)3] 3, in which two molecules of carbon dioxide react with the hydrides to produce formate ligands. Treating 1 with an organozinc(ii) complex, [Zn(C6F5)2], affords a hetero-tetrametallic CuI2ZnII2 complex, [Cu2(µ:κ3(PPC)-dppm′)2\{Zn(C6F5)2\}2] 4. Complex 4 features two cationic Cu(i) and two anionic Zn(ii) centres, adopting an unusual copper zincate speciation, and reacts with carbon dioxide to form a bis(carboxylate)-CuI2ZnII2 complex, [Cu2(µ:κ4(PPOO)-dppm″)2\{Zn(C6F5)2\}2] 5; carbon dioxide inserts into the Zn–C bond and forms a new C–C bond with the methine carbon of the dppm′ ligand. Overall, the structures and reactivity indicate that CuI sites readily form hydrides, on exposure to hydrogen; these cuprous hydrides react with CO2 to produce formate, and cuprous zincates react with CO2 to afford carboxylates.",

author = "Cowie, \{Bradley E.\} and Andreas Phanopoulos and Shaffer, \{Milo S.P.\} and Williams, \{Charlotte K.\}",

year = "2026",

month = jan,

day = "7",

doi = "10.1039/d5sc05666g",

language = "English",

volume = "17",

pages = "564--578",

journal = "Chemical Science",

issn = "2041-6520",

publisher = "Royal Society of Chemistry",

number = "1",

}

TY - JOUR

T1 - Structural and reactivity investigations using organo-copper(i) and zinc(ii) complexes with hydrogen and carbon dioxide

AU - Cowie, Bradley E.

AU - Phanopoulos, Andreas

AU - Shaffer, Milo S.P.

AU - Williams, Charlotte K.

PY - 2026/1/7

Y1 - 2026/1/7

N2 - Heterogeneous copper zinc catalysts are widely used in syn-gas or carbon dioxide hydrogenation to methanol, but the structures and reactivity at the catalytic active sites are still not fully understood. Well-defined metal complexes and clusters may help reveal the structures of key intermediates, including for catalytic reactions involving gaseous species. Here, a tri-copper(i) complex, [Cu3{µ:κ3(PPC)-dppm′}2{µ:κ2(PP)-dppm′}] 1 (dppm′ = [(Ph2P)2CH]−) is used as the starting point to investigate reactivity with hydrogen and carbon dioxide in solution and at low temperatures (20–60 °C) and gas pressures (1 bar or lower). Complex 1 reacts with hydrogen to afford a copper-hydride cluster, [Cu5(µ-H)(µ3-H)2(µ:κ3(PPC)-dppm′)2(µ:κ2(PP)-dppm)2] 2, which contains five CuI centres and three hydrido ligands. The reaction of 2 with carbon dioxide provides a tri-copper(i)-bis(formate)(hydrido) complex, [Cu3(µ3-H)(κ1(O)-O2CH)(µ:κ2(OO)-O2CH)(µ:κ2(PP)-dppm)3] 3, in which two molecules of carbon dioxide react with the hydrides to produce formate ligands. Treating 1 with an organozinc(ii) complex, [Zn(C6F5)2], affords a hetero-tetrametallic CuI2ZnII2 complex, [Cu2(µ:κ3(PPC)-dppm′)2{Zn(C6F5)2}2] 4. Complex 4 features two cationic Cu(i) and two anionic Zn(ii) centres, adopting an unusual copper zincate speciation, and reacts with carbon dioxide to form a bis(carboxylate)-CuI2ZnII2 complex, [Cu2(µ:κ4(PPOO)-dppm″)2{Zn(C6F5)2}2] 5; carbon dioxide inserts into the Zn–C bond and forms a new C–C bond with the methine carbon of the dppm′ ligand. Overall, the structures and reactivity indicate that CuI sites readily form hydrides, on exposure to hydrogen; these cuprous hydrides react with CO2 to produce formate, and cuprous zincates react with CO2 to afford carboxylates.

AB - Heterogeneous copper zinc catalysts are widely used in syn-gas or carbon dioxide hydrogenation to methanol, but the structures and reactivity at the catalytic active sites are still not fully understood. Well-defined metal complexes and clusters may help reveal the structures of key intermediates, including for catalytic reactions involving gaseous species. Here, a tri-copper(i) complex, [Cu3{µ:κ3(PPC)-dppm′}2{µ:κ2(PP)-dppm′}] 1 (dppm′ = [(Ph2P)2CH]−) is used as the starting point to investigate reactivity with hydrogen and carbon dioxide in solution and at low temperatures (20–60 °C) and gas pressures (1 bar or lower). Complex 1 reacts with hydrogen to afford a copper-hydride cluster, [Cu5(µ-H)(µ3-H)2(µ:κ3(PPC)-dppm′)2(µ:κ2(PP)-dppm)2] 2, which contains five CuI centres and three hydrido ligands. The reaction of 2 with carbon dioxide provides a tri-copper(i)-bis(formate)(hydrido) complex, [Cu3(µ3-H)(κ1(O)-O2CH)(µ:κ2(OO)-O2CH)(µ:κ2(PP)-dppm)3] 3, in which two molecules of carbon dioxide react with the hydrides to produce formate ligands. Treating 1 with an organozinc(ii) complex, [Zn(C6F5)2], affords a hetero-tetrametallic CuI2ZnII2 complex, [Cu2(µ:κ3(PPC)-dppm′)2{Zn(C6F5)2}2] 4. Complex 4 features two cationic Cu(i) and two anionic Zn(ii) centres, adopting an unusual copper zincate speciation, and reacts with carbon dioxide to form a bis(carboxylate)-CuI2ZnII2 complex, [Cu2(µ:κ4(PPOO)-dppm″)2{Zn(C6F5)2}2] 5; carbon dioxide inserts into the Zn–C bond and forms a new C–C bond with the methine carbon of the dppm′ ligand. Overall, the structures and reactivity indicate that CuI sites readily form hydrides, on exposure to hydrogen; these cuprous hydrides react with CO2 to produce formate, and cuprous zincates react with CO2 to afford carboxylates.

UR - https://www.scopus.com/pages/publications/105026657560

U2 - 10.1039/d5sc05666g

DO - 10.1039/d5sc05666g

M3 - Article

AN - SCOPUS:105026657560

SN - 2041-6520

VL - 17

SP - 564

EP - 578

JO - Chemical Science

JF - Chemical Science

IS - 1

ER -

Structural and reactivity investigations using organo-copper(i) and zinc(ii) complexes with hydrogen and carbon dioxide

Abstract

Data Availability Statement

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Cite this