In memoriam of Reinhard Schmutzler Foreword to a special issue of Phosphorus, Sulfur, and Silicon and the Related Elements

Reinhard Schmutzler was born on July 26, 1934, in Schwabach, a small town in northern Bavaria, Germany, and passed away on July 24, 2014, in Braunschweig, Germany, a few days before his 80^th birthday. For more than 50 years he was an outstanding chemist contributing a manifold of creative publications to Phosphorus and Fluorine Chemistry. His studies spanned a wide range, covering structural and spectroscopic aspects, combined with the synthesis of novel ligands and coordination compounds. Reinhard Schmutzler educated numerous students and generously hosted an impressive number of visiting scientists. His hospitality and support was legendary, as will be described subsequently in a dedicated paper by his co-worker and friend Martin Murray.

I met Reinhard Schmutzler for the first time in the second half of the 1960s at Aachen, when he gave a vivid talk about NMR spectroscopic investigations on phosphorus-fluorine-compounds. This first contact started discussions, letters, visits and finally led to my post doc studies (1970-1971) at the University of East Anglia, Norwich, UK, with Norman Sheppard (1921-2015) heading the Department of Physical Chemistry. I learned NMR spectral analysis, experimental techniques, and computing in the group of Robin K. Harris, a friend and colleague of Reinhard Schmutzler´s. A good year passed, which initiated my forthcoming interests and activities at Düsseldorf.

Our research areas overlapped in several aspects of sterically demanding substituents attached to phosphorus compounds. Particular attention was drawn towards t-butyl substituted compounds like t-BuP(X)Y₂^1,2, (t-Bu)₂P(X)Y^1,2 (X = :, O, S; Y = Halogen) and Me(t-Bu)(X)Y¹ (X = :, O, S; Y = Halogen, H, OH, OAlkyl, SH, SNa). Those compounds gave rise to IR and NMR studies on first order spin systems involving ¹H, ¹H{³¹P}, ³¹P, and ³¹P{¹H} techniques. More complex NMR spectra were observed for symmetric compounds like [Me(t-Bu)P(X)]₂Y^{1f, 3} (X = :, S; Y = -, O, S) which led to the hitherto unknown spin system of type [A₃M₉X]₂ or more generally to systems like [A_aM_mX]₂^1f also termed as [AR_tX_n]₂³.

Reinhard Schmutzler pioneered the chemistry of organophosphorus compounds with particularly demanding substituents AdP(X)Y₂, TrP(X)Y₂, and YoshP(X)Y₂ (Ad = Adamantyl; Tr = Trityl; Yosh = 2,4,6-tris-t-butylphenyl) and studied corresponding ligands and related coordination compounds.^2a,4

I shared a second area in preparative chemistry and NMR spectroscopy with Reinhard Schmutzler. We were intrigued by C- and P-chiral and pseudo-chiral organophosphorus compounds. Main interests concentrated on menthyl-P compounds like LP(X)Y₂, DP(X)Y, L₂P(X)Y, LDP(X)Y, LRP(X)Y⁵ (L = L-menthyl; D = D-menthyl; R = Alkyl, Aryl; X = :, O, S; Y = Halogen). Stereo specific chemical shifts δ_H, δ_C, δ_P, and coupling constants ⁿJ_HH, ⁿJ_PH, ⁿJ_PC were determined and supported by molecular modeling.

Menthyltiophosphoryldifluoride LP(S)F₂ allowed us to evaluate the geminal coupling constant ²J_FF by analysis of the ABX system affiliated with the ¹⁹F{¹H} and ³¹P{¹H} NMR spectra of LP(S)F₂.⁶ Achiral compounds RP(X)F₂ (X = :, O, S); R = Alkyl, Aryl)⁷ yield A₂X systems, where ²J_FF is “hidden” and inaccessible for standard ¹⁹F{¹H} and ³¹P{¹H} spectra.

Certainly, there is so much more to remember and report in memoriam of Reinhard Schmutzler, as will be apparent by subsequent dedications in this special issue. The phosphorus community will miss Reinhard Schmutzler, who served for many years as author, referee, and distinguished member of the editorial board of Phosphorus, Sulfur, and Silicon and the Related Elements.